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Distribution Changes of Small Fishes in Streams of Missouri from the 1940s to the 1990s by MATTHEW R. WINSTON Missouri Department of Conservation, Columbia, MO 65201 February 2003

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Distribution Changes of Small Fishes

in Streams of Missouri

from the 1940s to the 1990s

by MATTHEW R. WINSTON

Missouri Department of Conservation, Columbia, MO 65201

February 2003

2

CONTENTS Page

Abstract……………………………………………………………………………….. 8

Introduction…………………………………………………………………………… 10

Methods……………………………………………………………………………….. 17

The Data Used………………………………………………………………… 17

General Patterns in Species Change…………………………………………... 23

Conservation Status of Species……………………………………………….. 26

Results………………………………………………………………………………… 34

General Patterns in Species Change………………………………………….. 30

Conservation Status of Species……………………………………………….. 46

Discussion…………………………………………………………………………….. 63

General Patterns in Species Change………………………………………….. 53

Conservation Status of Species………………………………………………. 63

Acknowledgments……………………………………………………………………. 66

Literature Cited……………………………………………………………………….. 66

Appendix……………………………………………………………………………… 72

FIGURES

1. Distribution of samples by principal investigator…………………………. 20

2. Areas of greatest average decline…………………………………………. 33

3. Areas of greatest average expansion………………………………………. 34

4. The relationship between number of basins and ……………………….. 39

5. The distribution of for each reproductive group………………………... 40

3

6. The distribution of for each family……………………………………… 41

7. The distribution of for each trophic group……………...………………. 42

8. The distribution of for each faunal region………………………………. 43

9. The distribution of for each stream type………………………………… 44

10. The distribution of for each range edge…………………………………. 45

11. Modified IUCN categories versus existing state rank…………………… 52

12. Time path of samples made by Harry……………………………………. 55

13. Water level differences before and during the two sample periods……… 56

TABLES

1. Species analyzed in this paper……………………………………………. 11

2. The IUCN and modified criteria for critically endangered,

endangered, and vulnerable………………………………………………. 26

3. Change in species occurrence, 1940s versus 1990s………………………. 30

4. Species showing regional decline………………………………………… 36

5. Species showing regional expansion……………………………………... 37

6. Extinction correlates and sample adequacy………………………………. 46

7. Abundance of Ozark species in 1990s samples where they

showed expansion into the southern and western plains…………………. 57

APPENDIX TABLES

1. Species traits used in this analysis………………………………………… 72

4

APPENDIX FIGURES (in alphabetical order)

1. Arkansas River orangethroat darter……………...………………………... 75

2. Banded darter…………………………………………………………….... 76

3. Banded sculpin…………………………………………………………….. 77

4. Bigeye chub……………………………………………………………… 78

5. Bigeye shiner…………………………………………………………….. 79

6. Bigmouth shiner……………………….…………………………………. 80

7. Blacknose shiner…………………………………………………………… 81

8. Blackside darter……………………………………………………………. 82

9. Blackspotted topminnow………………………………………………… 83

10. Blackstripe topminnow…………………………………………………….. 84

11. Blacktail shiner…………………………………………………………... 85

12. Bleeding shiner…………………………………………………………….. 86

13. Bluegill…………………………………………………………………… 87

14. Bluestripe darter…………………………………………………................. 88

15. Bluntface shiner……………………………………………………………. 89

16. Bluntnose darter………………………………………………………….. 90

17. Bluntnose minnow……………………………………………….………. 91

18. Brook silverside………………………………………………………….. 92

19. Bullhead minnow…………………………………………………………. 93

20. Cardinal shiner…………………………………………………………… 94

21. Central stoneroller………………………………………………………… 95

22. Common shiner……………………………………………………………. 96

5

23. Creek chub…………………………………………………………………. 97

24. Creek chubsucker………………………………………………………….. 98

25. Duskystripe shiner…………………………………………………………. 99

26. Eastern redfin shiner………………………………………………………. 100

27. Emerald shiner…………………………………………………………… 101

28. Fathead minnow……………………………………………………………. 102

29. Freckled madtom………………………………………………………… 103

30. Ghost shiner……………………………………………………………… 104

31. Gilt darter………………………………………………………………… 105

32. Golden shiner…………………………………………………………….. 106

33. Gravel chub………………………………………………………………. 107

34. Greenside darter……………………………………………….................. 108

35. Green sunfish……………………………………………………………... 109

36. Hornyhead chub……………………………………………….................. 110

37. Johnny darter……………………………………………………………... 111

38. Largescale stoneroller…………………………………………………….. 112

39. Longear sunfish…………………………………………………………… 113

40. Meramec River saddled darter……………………………………………. 114

41. Mimic shiner……………………………………………………………… 115

42. Mississippi silvery minnow………………………………………………. 116

43. Missouri saddled darter…………………………………………………… 117

44. Mottled/Ozark sculpin………………………………………..................... 118

45. Northern logperch…………………………………………………………. 119

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46. Northern orangethroat darter………………………………………………..120

47. Northern studfish………………………………………………………… 121

48. Ohio logperch…………………………………………………….................122

49. Orangespotted sunfish……………………………………………………… 123

50. Ozark chub……………………………………………………………….. 124

51. Ozark logperch…………………………………………………………… 125

52. Ozark madtom……………………………………………………………… 126

53. Ozark minnow………………………………………………….................... 127

54. Ozark shiner……………………………………………………………… 128

55. Pallid shiner……………………………………………………………… 129

56. Peppered chub……………………………………………………………… 130

57. Plains minnow……………………………………………………………. 131

58. Plains topminnow………………………………………………………… 132

59. Pugnose minnow…………………………………………………………… 133

60. Rainbow darter…………………………………………………………… 134

61. Red shiner………………………………………………………………… 135

62. Redspot chub…………………………………………………….................. 136

63. Redspotted sunfish…………………………………………………………. 137

64. Ribbon shiner……………………….…………………………………….. 138

65. Rosyface shiner…………………………………………………………….. 139

66. Sand shiner…………………………………………………………………. 140

67. Silver chub…………………………………………………………………. 141

68. Slenderhead darter…………………………………………………………. 142

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69. Slender madtom……………………………………………………………. 143

70. Slough darter…………………………………………………….................. 144

71. Southern redbelly dace…………………………………………………… 145

72. Speckled darter…………………………………………………………… 146

73. Spotfin shiner…………………………………………………………….. 147

74. Steelcolor shiner…………………………………………………………….148

75. Stippled darter……………………………………………………………. 149

76. Stonecat…………………………………………………………………… 150

77. Striped fantail darter……………………………………………………… 151

78. Striped shiner…………………………………………………………….. 152

79. Suckermouth minnow…………………………………………................. 153

80. Tadpole madtom…………………………………………………………. 154

81. Telescope shiner………………………………………………………….. 155

82. Topeka shiner…………………………………………………………….. 156

83. Trout-perch……………………………………………………................. 157

84. Warmouth………………………………………………………………… 158

85. Wedgespot shiner………………………………………………………… 159

86. Weed shiner………………………………………………………………. 160

87. Western mosquitofish…………………………………………………….. 161

88. Western redfin shiner……………………………………………………... 162

89. White River orangethroat darter……………………………….................. 163

90. Whitetail shiner…………………………………………………………… 164

91. Yoke darter………………………………….…………………................. 165

8

ABSTRACT

One of the strategic goals of the Missouri Department of Conservation is to

preserve and restore the state’s biodiversity including the 232 fish species and subspecies

in Missouri. Meeting this goal requires knowledge of changes in distribution and habitat

of each species. I compared data from fish community samples made with seines

throughout most of the state between 1938 and 1941 with samples made similarly

between 1986 and 2001. My first objective was to investigate whether species

distributions in Missouri had changed, where the most change occurred, and what species

traits were associated with change. My second objective was to apply the International

Union for the Conservation of Species (IUCN) criteria to each species to assess

probability of extirpation in the state. My methods were based on five measures. For each

species, I assessed change in distribution over time. In the reaches where a species was

known to occur in the 1990s, I assessed total length of the reaches, the proportion of

samples with the species, isolation of reaches, and an index of population size in isolated

reaches. Of the 91 species with large enough sample sizes for analysis, four showed no

change in distribution over time, 49 declined, and 38 expanded. Decline was greatest in

the northern Ozarks; expansion was greatest in the western and southern plains. Over half

of the species that showed decline in the Ozarks were plains species, and over half of the

species that expanded into the plains were Ozark species. Out of 32 species’ traits tested,

seven were associated with decline: membership in the family Cyprinidae (minnows),

species characteristic of large Ozark rivers, large plains rivers, small plains rivers, plains

headwaters, clear lowland ditches, and species with the northwestern edge of their range

in Missouri. Membership in the family Cyprinidae was by far the most important trait

9

associated with decline. Over 96% of the species that declined were associated with at

least one of these seven trait categories. Expansion was associated with species

characteristic of small Ozark rivers, Ozark creeks, and lowland standing waters, but these

were not strong relationships. I discuss nine alternative explanations for the general

patterns I found: sampling bias, grazing in riparian forests, plowing of soils for row-crop

agriculture, predation, range size, climate change, Missouri River modifications, drought,

and channel downcutting. Four species met the IUCN criteria for highly endangered,

eight species met the criteria for endangered, and eight species met the criteria for

vulnerable. Agreement between the IUCN categories and the existing state ranks was

fairly strong; however, the IUCN categories encompassed only the most endangered

ranks of the state list. Three unlisted species, Arkansas saddled darter (Etheostoma

euzonum euzonum), Current River saddled darter (E. e. erizonum), and weed shiner

(Notropis texanus), met the IUCN criteria and should be added to the Missouri species of

conservation concern checklist. IUCN policy states that species not be downlisted until

another survey at least five years later corroborates the earlier downlisting

recommendation. Periodic community samples are the most cost-effective way to

monitor fish species distributions in Missouri. As shown in this analysis, community

samples can provide insight into general distribution changes and provide information to

assess conservation status.

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INTRODUCTION

As of 2002 there were 200 native and 12 introduced species of fishes that

reproduce in Missouri waters. If one includes the well-defined forms that have been

described for some species (such as the cave-inhabiting form of the banded sculpin

Cottus carolinae), species that migrate into Missouri (such as the bull shark Carcharinus

leucas), and the one species extirpated from the state (the pallid shiner Notropis amnis), a

total of 230 species or easily recognizable forms make up the Missouri fish fauna.

The most efficient way to monitor the fish species of Missouri is to make

community samples. A community is defined as all organisms that can potentially

interact (i.e., eating each other, competing for habitat, etc.). So a community includes the

fishes as well as all the other organisms in and around a section of stream. A community

sample is a sample of organisms from the community made with a particular sample gear.

Community samples are efficient because one gear often samples many species so

information is gained on multiple species. However, because all sample gears are

selective, most community samples include only a small part of the entire community.

This study includes only those species that are efficiently caught, as adults, with

small seines. This includes small stream fishes and excludes large fish species (those

reaching maximum lengths of 12 inches or more), cave species, obligate big river species

(too deep to seine), and lampreys (can be seined only in early spring). Although

crayfishes and the glass shrimp (Palaemonetes kadiakensis) are also efficiently caught

with seines, they were not included in this analysis because data on these species was not

consistently collected. Most small stream fishes of Missouri are described in Pflieger

(1997). Taxonomic changes that have occurred since 1997 include the splitting off of the

11

brook darter (Etheostoma burri) and current darter (E. uniporum) from the orangethroat

darter (E. spectabile; Ceas and Page 1997), the splitting of the Missouri saddled darter (E.

tetrazonum) into two species (Switzer and Wood 2002), and the renaming of the speckled

chub (Macrhybopsis aestivalis) to the peppered chub (M. tetranema; Eisenhour 1999).

For the central stoneroller, I use the binomial Campostoma anomalum (Robins et al.

1991) rather than C. pullum as used in Pflieger (1997). This makes 143 species or forms

(called species from here on) that are included in this study (Table 1).

Table 1. Species analyzed in this paper. Common name Scientific name Alabama shad Alosa alabamae Arkansas darter Etheostoma cragini Arkansas River orangethroat darter Etheostoma spectabile squamosum Arkansas saddled darter Etheostoma euzonum euzonum Banded pigmy sunfish Elassoma zonatum Banded sculpin Cottus carolinae Bantam sunfish Lepomis symmetricus Barred fantail darter Etheostoma flabellare flabellare Banded darter Etheostoma zonale Bigeye chub Notropis amblops Bigeye shiner Notropis boops Bigmouth shiner Notropis dorsalis Blacknose shiner Notropis heterolepis Blackside darter Percina maculata Blackspotted topminnow Fundulus olivaceus Blackstripe topminnow Fundulus notatus Blacktail shiner Cyprinella venusta Bleeding shiner Luxilus zonatus Bluegill Lepomis macrochirus Bluestripe darter Percina cymatotaenia Bluntface shiner Cyprinella camura Bluntnose darter Etheostoma chlorosomum Bluntnose minnow Pimephales notatus Brassy minnow Hybognathus hankinsoni Brindled madtom Noturus miurus Brook darter Etheostoma burri Brook silverside Labidesthes sicculus Bullhead minnow Pimephales vigilax

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Table 1 (continued). Species analyzed in this paper. Common name Scientific name Cardinal shiner Luxilus cardinalis Central mudminnow Umbra limi Central stoneroller Campostoma anomalum Channel darter Percina copelandi Checkered madtom Noturus flavater Common shiner Luxilus cornutus Creek chub Semotilus atromaculatus Creek chubsucker Erimyzon oblongus Crystal darter Crystallaria asprella Current darter Etheostoma uniporum Current River saddled darter Etheostoma euzonum erizonum Cypress darter Etheostoma proleiare Cypress minnow Hybognathus hayi Dollar sunfish Lepomis marginatus Dusky darter Percina sciera Duskystripe shiner Luxilus pilsbryi Eastern redfin shiner Lythrurus umbratilis cyanocephalus Eastern slim minnow Pimephales tenellus parviceps Emerald shiner Notropis atherinoides Fathead minnow Pimephales promelas Flier Centrarchus macropterus Freckled madtom Noturus nocturnus Ghost shiner Notropis buchanani Gilt darter Percina evides Golden shiner Notemigonus crysoleucas Golden topminnow Fundulus chrysotus Goldstripe darter Etheostoma parvipinne Gravel chub Erimystax x-punctatus Green sunfish Lepomis cyanellus Greenside darter Etheostoma blennioides Harlequin darter Etheostoma histrio Hornyhead chub Nocomis biguttatus Ironcolor shiner Notropis chalybaeus Johnny darter Etheostoma nigrum Lake chubsucker Erimyzon sucetta Largescale stoneroller Campostoma oligolepis Least darter Etheostoma microperca Longear sunfish Lepomis megalotis Longnose darter Percina nasuta Meramec River saddled darter Etheostoma tetrazonum Mimic shiner Notropis volucellus Mississippi silvery minnow Hybognathus nuchalis Missouri saddled darter Etheostoma tetrazonum Mottled sculpin Cottus bairdi*

13

Table 1 (continued). Species analyzed in this paper. Common name Scientific name Mountain madtom Noturus eleutherus Mud darter Etheostoma asprigene Neosho madtom Noturus placidus Niangua darter Etheostoma nianguae Northern logperch Percina caprodes semifasciata Northern orangethroat darter Etheostoma spectabile spectabile Northern studfish Fundulus catenatus Ohio logperch Percina caprodes caprodes Orangespotted sunfish Lepomis humilis Ozark chub Erimystax harryi Ozark madtom Noturus albater Ozark minnow Notropis nubilus Ozark logperch Percina caprodes fulvitaenia Ozark sculpin Cottus hypselurus* Ozark shiner Notropis ozarcanus Pallid shiner Notropis amnis Peppered chub Macrhybopsis tetranema Pirate perch Aphredoderus sayanus Plains killifish Fundulus zebrinus Plains minnow Hybognathus placitus Plains orangethroat darter Etheostoma spectabile pulchellum Plains topminnow Fundulus sciadicus Pugnose minnow Opsopoeodus emiliae Rainbow darter Etheostoma caeruleum Redear sunfish Lepomis microlophus Redfin darter Etheostoma whipplei Red shiner Cyprinella lutrensis Redspot chub Nocomis asper Redspotted sunfish Lepomis miniatus Ribbon shiner Lythrurus fumeus River darter Percina shumardi Rosyface shiner Notropis rubellus Sabine shiner Notropis sabinae Saddleback darter Percina vigil Sand shiner Notropis ludibundus Scaly sand darter Ammocrypta vivax Silver chub Macrhybopsis storeriana Silverjaw minnow Notropis buccatus Slenderhead darter Percina phoxocephala Slender madtom Noturus exilis Slough darter Etheostoma gracile Southern redbelly dace Phoxinus erythrogaster Speckled darter Etheostoma stigmaeum Spotfin shiner Cyprinella spiloptera

14

Table 1 (continued). Species analyzed in this paper. Common name Scientific name Spring cavefish Forbesichthys agassizi Stargazing darter Percina uranidea Starhead topminnow Fundulus dispar Steelcolor shiner Cyprinella whipplei Stippled darter Etheostoma punctulatum Stonecat Noturus flavus Striped fantail darter Etheostoma flabellare lineolatum Striped shiner Luxilus chrysocephalus Suckermouth minnow Phenacobius mirabilis Swamp darter Etheostoma fusiforme Tadpole madtom Noturus gyrinus Taillight shiner Notropis maculatus Telescope shiner Notropis telescopus Topeka shiner Notropis topeka Trout-perch Percopsis omiscomaycus Warmouth Lepomis gulosus Wedgespot shiner Notropis greenei Weed shiner Notropis texanus Western mosquitofish Gambusia affinis Western redfin shiner Lythrurus umbratilis umbratilis Western sand darter Ammocrypta clara Western silvery minnow Hybognathus argyritis Western slim minnow Pimephales tenellus tenellus Whitetail shiner Cyprinella galactura White River fantail darter Etheostoma flabellare White River orangethroat darter Etheostoma spectabile Yoke darter Etheostoma juliae ------------------------------------------------------------------------------------------------------------ *Cottus hypselurus was combined with C. bairdi.

In this study, I used community samples made statewide in two time periods,

1938-1941 (the 1940s) and 1986-2001 (the 1990s). From these data, I calculated the

change in distribution over time for each species. I then asked two questions: Where in

the state has change occurred most intensively? What types of species (e.g., minnow

species, Ozark species) have changed? This information can help generate hypotheses on

what has caused the change. It can also provide surrogate data for rare species. It is

difficult to obtain good data on rare species precisely because they are rare. However, if a

15

rare species happens to be a minnow species, for example, and if most common minnow

species have declined, then one can conclude that the rare species is likely to have

declined as well.

Community samples can also provide estimates of each species’ probability of

extinction, which is the basic measure for species conservation. The International Union

for the Conservation of Nature (IUCN) has developed criteria to estimate the probability

of extinction for a species (Mace and Lande 1991; Mace 1994; www.iucn.org/themes/ssc/

redlists/ssc-rl-c.htm). Six basic measures are used to estimate probability of extinction:

abundance, rate of reduction in abundance over time, fluctuation in abundance over time,

area of occurrence, number of subpopulations, and fragmentation of subpopulations.

These basic measures are often costly to obtain. They are usually only estimated for

species listed under the U.S. Endangered Species Act or for economically valuable

species, but they are correlated with other measures that can be derived from inexpensive

community samples. Abundance is correlated with proportion of sites occupied (Gaston

1996; Hanski and Gyllenberg 1997; Johnson 1998). The same correlation can be used for

the rate of reduction in abundance over time and fluctuation in abundance over time. For

area of occurrence, IUCN recommends using the area of a convex polygon around known

occurrences. From community samples, we know the stream reaches where a species is

found. From this, the length of stream can be calculated. Because streams are almost

linear features, this should be highly correlated with the area of the stream. For number of

subpopulations, the number of reaches in which a species occurs can be used. A reach

can be defined as a length of stream bounded by changes in stream order. By this

definition, each reach is a well-defined landscape unit that is internally homogenous

16

compared to other reaches, and each reach will be connected to other reaches at (usually)

no more than two points. The distribution of the federally listed tan riffleshell mussel

(Epioblasma florentina walkeri) provides a vivid example of the importance of this

definition of reach (Shaffer and Stein 2000). In 1998, the only two populations of this

species in the world existed in the Clinch River, Virginia, and Indian Creek, a small

tributary to the Clinch River. A toxic spill completely killed off the population in the

Clinch River, leaving only the one population in Indian Creek. Although the toxic spill

flowed past the mouth of Indian Creek, it did not affect the mussels upstream of the

mouth in Indian Creek. Lastly, isolation of subpopulations can be estimated by looking

for reaches in which a species occurs separated by reaches in which the species does not

occur (e.g., Echelle et al. 1975).

The IUCN criteria are structured as thresholds. If a species meets certain criteria,

it is listed as critically endangered, endangered, or threatened. The criteria are based on

the six measures of probability of extinction. A threshold can either be an individual

measure (e.g., “Population estimated to number less than 50 mature individuals”) or it

can be a combination of measures (e.g., “Population estimated to number less than 250

mature individuals and an estimated continuing decline of at least 25% within 3 years”).

Likewise, variables derived from community samples can be used to construct these

thresholds.

The state of Missouri has a list of species of conservation concern (Missouri

Natural Heritage Program 2003). One of the functions of this list is to draw attention to

species which are in danger of being extirpated from the state or, in the case of state

endemics, which are in danger of complete extinction. Also, the state status “endangered”

17

provides a small amount of protection by law. The list should be regularly updated with

the best data available. The IUCN thresholds are objective criteria for making listing

evaluations.

I had two primary objectives for this study. My first primary objective was to look

for general patterns in the change of species distributions over time. I looked for spatial

patterns in the overall decline or expansion in the range of species within the state of

Missouri. I asked: Do particular regions within the state show greater change compared to

other regions? I then correlated general species traits with expansion and decline of

species. I asked: What types of species changed in distribution? Although pinpointing the

causes of decline or expansion of species was beyond the scope of this study, I used

general patterns to generate hypotheses of why species have changed.

My second primary objective concerned individual species. I used modified

IUCN criteria to evaluate each species’ probability of extinction. I compared the present

rank of species listed in the Missouri Species of Conservation Concern Checklist with the

ranks calculated using the modified IUCN criteria. Corollary to this, I evaluated the

number and distribution of samples within the range of each species. The goal for

establishing baseline data for future evaluations should be an adequate number of

samples evenly distributed throughout the range of each species.

METHODS

The Data Used

The Missouri Department of Conservation (MDC) maintains a database of fish

community samples made in the state since 1929. Copies of field and laboratory data

18

sheets are also on file. The data are highly heterogeneous and unstandardized, as would

be expected. My first task was to select the data to be used for the analysis.

In 1940 and 1941, George V. Harry, a graduate student under Carl Hubbs at the

University of Michigan, made 345 community samples in the state. He used a 25-ft bag

seine, a 20-ft seine, and a 6-ft seine. He recorded locality and species caught for all

samples. He recorded effort, in terms of total time spent sampling, for 288 of the samples.

He did not record number of specimens caught. I assumed that total time spent sampling

was the time from when the first seine haul was begun to when the last seine haul was

finished. He sampled throughout the state except in the Eleven Point, Current, Black, St.

Francis, Castor, and Whitewater river systems.

Harry made 23 samples in reaches that would be inundated in the future by

reservoirs. I did not include these samples in the analysis for several reasons. First,

although most of the species that occurred in those reaches are probably now gone, I

could not say for certain which ones were gone. There is some evidence that even state-

listed Ozark endemics such as the checkered madtom and the longnose darter may be

able to live in reservoirs. No systematic research has been done in Missouri on this

question. Second, for those that are gone, the cause of their extirpation is obvious. It

requires little analysis. The effects of reservoirs have been known for a long time and

certainly have been accounted for in past conservation evaluations. Third, there is little

chance that the habitats will be restored to an uninundated state at any time in the

medium-term future. Fourth, reservoirs affect so many species that if I included Harry’s

samples in the analysis and assumed that all small species have disappeared from

inundated reaches, almost every species would show strong decline, obscuring other

19

possible patterns.

Harry also made nine samples in the Missouri and Mississippi Rivers. I did not

include Missouri River or Mississippi River samples in the analysis because seines are

inefficient even for small species in these systems.

At the same time as Harry was sampling, two biologists sampled the systems that

Harry skipped. Carl B. Obrecht made 49 samples in the Eleven Point and Current river

systems, and Aden C. Baumann made 71 samples in the Black, St. Francis, Castor, and

Whitewater river systems. They used seines of unknown size and recorded locality and

species caught, but did not make any record of effort such as total time spent sampling or

number of specimens caught.

Although MDC has records of 246 other samples made in Missouri before 1947,

only 19 have effort recorded. Most of these samples were made by Hugh Denny in 1938

and were concentrated in the middle reaches of the main channels of the Eleven Point and

Current Rivers. He used seines of unknown size. He recorded the total number of

individuals of each species he caught but did not record total time spent sampling.

For this analysis, I used all of Harry’s samples (except those inundated by

reservoirs and in the big rivers), eight of Denny’s samples, and three others for a total of

269 samples (Figure 1). I decided not to use Obrecht’s or Baumann’s samples because

effort was not recorded. This left a large area of the southeastern Ozarks without samples.

So, this analysis is statewide except for the Black, St. Francis, Castor, and Whitewater

river systems, and parts of the Eleven Point and Current river systems (Figure 1).

I paired each past sample with a present sample that was nearby (in the same

location, if possible), of similar stream order, and of similar total time spent sampling or

20

total number of individuals. I had 2029 community samples made in the state from 1986

to 2001 from which to choose. Paired t-tests on total time spent sampling and total

number of specimens caught were not significant (P > 0.10). I repeated the tests for the

samples within the range of each species. Some species showed significant differences (P

< 0.05), so I substituted other samples from the 1990s until there was no significant

difference. Of the 269 present samples chosen, 96 were made by Sue A. Bruenderman, 62

by William L. Pflieger, and the remaining 111 samples made by 17 other MDC biologists

(Figure 1). Eighteen samples were made from 1986 to 1989, 75 from 1990 to 1992, 120

from 1993 to 1996, and 56 from 1997 to 2001. Gear used was seines; 80% of the samples

were taken using 15-ft by 6-ft and 6-ft by 4-ft seines; the rest used 25-ft bag, 15-ft, and 6-

ft seines. From here on, I refer to the 269 earlier samples as 1940s samples and the 269

21

later samples as 1990s samples. All samples were made at one location on one date, i.e.,

no samples were made up of more than one sample pooled from different dates or

different locations.

Because a longer seine was used for the 1940s samples, I expected that more large

fish were caught in the 1940s. Although large fish pass through a small fish stage during

development that would be vulnerable to capture by both 15-ft and 25-ft seines, size

classes were not differentiated in the data. So in order to avoid introducing bias into the

analysis, I omitted large species from the analysis. I defined large species as those with

maximum length greater than 12 inches.

The IUCN criteria are based on adult individuals. However, there was no

differentiation between adult and immature fish in either the 1940s or 1990s samples.

Because the modified IUCN criteria used in this analysis are based on presence/absence,

this inconsistency should not invalidate the analysis.

For the purposes of analysis, I combined data for the mottled sculpin and Ozark

sculpin because there seemed to be confusion in identification of the two species.

Although the Alabama shad reaches a maximum length greater than 12 inches, I included

it in the analysis because adults are almost never caught with small seines, and the young-

of-year are present in streams and are vulnerable to seines throughout the warm months.

I defined the range of a species as all the reaches in Missouri where the species

had ever been collected as found in the MDC Fish Community Database (consisting of

5,182 samples in October 2002). The less common a species was, the more likely it was

that all reaches where it occurred would have been sampled, because less common

species have been surveyed more intensively.

22

I wanted to be sure that the samples used in this analysis were dispersed evenly or

randomly within the range of each species rather than being clumped in one part of the

range. I used a runs test (Sokal and Rohlf 1981) to check if the sampled reaches were

clumped within all the reaches that make up the range of a species. All reaches in

Missouri have been assigned a hierarchical stream number (Pflieger et al. 1982) in such a

way that, from the number, the upstream and downstream reaches can be ascertained as

well as the hierarchy of basins in which the reach is situated. When the reaches are sorted

in ascending sequence, those close together in the sequence will be both close in x and y

coordinates on a map and close in stream connectivity. Sampled reaches were assigned a

‘1’, unsampled reaches a ‘0’. If sampled reaches were clumped, they formed a series of

1’s and this pattern showed up as a runs-test z score less than zero. I deleted reaches from

the middle of the longest runs until the z score was greater than zero. This meant that

sampled reaches were distributed randomly or evenly relative to all the reaches where a

species had ever been sampled. A z score close to zero would result from a random

interspersion of 1’s and 0’s. The more positive the z score, the more the distribution of

reaches would resemble an even distribution of 1’s and 0’s (a distribution approaching

the form ‘01010101’). I considered both random and even distributions of sampled

reaches within unsampled reaches as adequate for further analysis.

Once I was assured that sampled reaches were distributed evenly or randomly

within the known range of each species, I needed to test whether the number of samples

within sampled reaches was evenly or randomly distributed for each species. I did not

want one reach to have many samples while the other reaches had few samples. To do

this, I checked that the mean-to-variance ratio of the number of samples per reach was

23

less than one. I applied this test to a diverse and representative subsample of species. In

all cases, the mean-to-variance ratio was less than one, so I did not apply this test to all

species. I expected this anyway because of the dispersed manner in which the 1940s

samples were distributed.

General Patterns in Species Change

My first primary objective was to look for general patterns in the change of

species distributions over time. I calculated the proportion of samples in which a species

was collected out of all samples made within its range. Here, my definition of range

changed from the way I used it above. Above, I defined a species’ range as all the reaches

in Missouri where the species had ever been collected according to the records in the

MDC fish community database. Here, I defined a species’ range as all the reaches where

the species had been collected in the samples selected for this analysis. This reduced

extent of a species’ range was necessary to exclude reaches in which the species had not

been collected in the samples selected for this analysis but that had been collected in

other samples in the MDC fish community database. These reaches did not add any

information concerning the difference between the 1940s and 1990s; they only reduced

equally the proportion of samples in which a species occurred in the two periods. I

defined a reach as a length of stream bounded by changes in stream order. Reaches with

more than nine 3rd-order or larger tributaries were evenly divided into shorter reaches

(Pflieger et al. 1982).

I calculated change as the percent change in proportion over time. Change varied

from -100 to greater than 100. A change of -100 meant that a species was collected in the

24

1940s but not in the 1990s. A change greater than 100 meant that a species more than

doubled the number of samples in which it was found over time. I calculated change only

for species with greater than or equal to five samples within their range in each period. A

sample large enough to actually test for a change in proportions over time with adequate

power would require at least 20 samples and often many more (Sokal and Rohlf 1981).

Because five was a low sample size, I did not do the test but I was able to include many

more species in the analysis.

I divided change into decline (change < 0) and expansion (change > 0), and

asked, “Where has most of the decline and expansion occurred?” To answer this, I

calculated for each species in each 8-digit USGS hydrological unit, the proportion of sites

occupied within the species’ range in the 1940s and in the 1990s. A low proportion in the

1940s would indicate expansion, and a low proportion in the 1990s would indicate

decline. I chose the 8-digit hydrological unit after experimenting with larger (6-digit) and

smaller (11-digit) scales; the 8-digit scale seemed the smallest scale feasible given the

number of samples per hydrological unit. I then calculated an average expansion and

average decline over all species within each 8-digit hydrological unit and mapped the

results using different shades for classes of the averages.

To interpret change further, I mapped each species separately. For the 1940s and

1990s, I mapped where the species was present and the samples made within the range of

the species. I looked for and noted areas with samples but no presences. These showed

local range expansion or contraction. I then tabulated which species declined or expanded

in different regions. I defined regions as follows. I used the plains, Ozark, and lowland

regions according to the aquatic faunal regions defined in Pflieger (1989a). The east

25

Ozarks included all streams flowing directly into the Mississippi River. The west Ozarks

included the Neosho and Sac river basins. The south Ozarks included the Eleven Point

and Current river basins. The north Ozarks included all Missouri River basin streams

except the Sac River basin. I also defined the White River basin as a separate region. The

east plains included all streams flowing directly into the Mississippi River. The west

plains included the west Osage River basin, the South Grand River basin, small Missouri

River tributaries just east of Kansas City, and all Missouri River tributaries upstream of

Kansas City. The south plains included the Saline River and Black River basins, and the

small tributaries to the Missouri River around Jefferson City. The northern plains

included all Grand River tributaries. I considered the lowlands as one region.

Along with where change occurred, I looked at what species traits were

associated with change. I first transformed change to make the values symmetrical about

zero change. I used the equation = loge(change + 101). This made the values bell-

shaped in distribution and put them on a scale of 1 (change = -100) to 4.615 (change = 0)

to 5.303 or more (change > 100). I looked at seven species traits (Appendix Table 1).

First, I plotted versus the number of 8-digit hydrological units in which a species was

ever collected according to the MDC fish community database and calculated a linear

regression and the proportion of variability explained by the linear model (R2). I

constructed box plots for the remaining traits. If the 25th percentile was near or above =

4.615 or the 75th percentile was near or below = 4.615, I concluded that a large

majority of the species with a particular trait had expanded or declined. I examined traits

that were known for all species in the analysis (Berkman and Rabeni 1987; Rabeni and

Smale 1995; Pflieger 1989; Pflieger 1997): family, reproductive group, feeding group,

26

region where species is most characteristic, characteristic stream type in its most

characteristic region, and range edge in Missouri not defined by a drainage boundary. It

should be noted that only trait categories with multiple species were examinable. I then

looked at which traits were most important by comparing unique species, i.e., those only

in one category.

Conservation Status of Species

My second primary objective was to evaluate the conservation status of each

species. I first designed thresholds similar to those used by the IUCN (Mace and Lande

1991; Mace 1994; www.redlist.org/info/categories_criteria2001.html).

The first IUCN threshold was based on straight population reduction (Table 2). I

measured this with change. Because the IUCN threshold was over a time period of ten

years, I had to take their thresholds and compound them to 50 years.

Table 2. The IUCN and modified criteria for critically endangered, endangered, and vulnerable. For clarity, details that do not apply to this analysis have been left out of the IUCN criteria. IUCN Modified Threshold 1 Highly endangered: A population size reduction of Change <= -99%. >= 80% within the next 10 years. Endangered: A population size reduction of >= Change <= -96%. 50% within the next 10 years. Vulnerable: A population size reduction of >= 30% Change <= -83%. within the next 10 years. Threshold 2 Highly endangered: Extent of occurrence estimated Rchlength <= 10 km. to be less than 100 km2 and both 1 and 2. 1. Severely fragmented or known to exist at 1. Fragmentation >= 0.5 or numreach <= 1 reach. only a single location. 2. Continuing decline. 2. Change <= -40% or membership in declined group. Endangered: Extent of occurrence estimated to be Rchlength <= 70 km. less than 5000 km2 and both 1 and 2. 1. Severely fragmented or known to exist at 1. Fragmentation >= 0.5 or numreach <= 5 reaches. no more than five locations. 2. Continuing decline. 2. Change <= -40% or membership in declined group. Vulnerable: Extent of occurrence estimated to be Rchlength <= 140 km. less than 20,000 km2 and both 1 and 2. 1. Severely fragmented or known to exist at 1. Fragmentation >= 0.5 or numreach <= 10 reaches. no more than 10 locations. 2. Continuing decline. 2. Change <= -40% or membership in declined group.

27

Threshold 3 Highly endangered: Population size estimated to Popsize <= 5. number less than 250 mature individuals and either 1 or 2. 1. Continuing decline of at least 25% within 1. Change <= -98%. three years. 2. Continuing decline and population 2. Change <= -40% or membership in declined group. structure in the form of either a or b. a. No subpopulation estimated to contain more a. Popsize <= 1 in all subpopulations. than 50 mature individuals. b. At least 90% of mature individuals b. At least 90% of popsize in one subpopulation. in one subpopulation Endangered: Population size estimated to number Popsize <= 50. less than 2500 mature individuals and either 1 or 2. 1. Continuing decline of at least 20% within 1. Change <= -89%. five years. 2. Continuing decline and population structure 2. Change <= -40% or membership in declined in the form of either a or b. group. a. No subpopulation estimated to a. Popsize <= 5 in all subpopulations. contain more than 250 mature individuals. b. At least 95% of mature individuals b. At least 95% of popsize in one subpopulation. in one subpopulation. Vulnerable: Population size estimated to number less Popsize <= 250. than 10,000 mature individuals and either 1 or 2. 1. Continuing decline of at least 10% within 10 years. 1. Change <= -40%. 2. Continuing decline and population structure 2. Change <= -40% or membership in declined group. in the form of either a or b. a. No subpopulation estimated to contain more a. Popsize <= 25 in all subpopulations. than 1000 mature individuals. b. All mature individuals in one subpopulation. b. 100% of popsize in one subpopulation. Threshold 4 Highly endangered: Population size estimated to Popsize <= 1. number fewer than 50 mature individuals. Endangered: Population size estimated to number Popsize <= 5. fewer than 250 mature individuals. Vulnerable: Either 1, 2, or 3. 1. Population size estimated to number 1. Popsize <= 25. fewer than 1000 mature individuals.

2. Area of occupancy less than 20 km2. 2. Rchlength <= 10 km. 3. Known to exist at no more than five locations. 3. Numreach <= 5 reaches.

The second IUCN threshold was based on a combination of low area of

occurrence, severe fragmentation or low occupancy, and decline (Table 2). The IUCN

recommendations for area of occurrence were obviously too high for small stream fishes.

For example, an area of occurrence of 100 km2 was part of the threshold for highly

endangered. But, considering that a wadeable stream varies from about 0.001 km to about

0.050 km wide, an area of 100 km2 would be a length of stream of 2,000 to 10,000 km.

These values are clearly much higher than what should be considered a criterion for

highly endangered for small stream fishes. The difference may be due to the fact that

small organisms generally require smaller habitat areas. Because I knew of no research in

28

this area for small stream fishes, I simply took the square root of the IUCN values. I

calculated rchlength as the total length of the reaches where a species was known to

occur, using data from the MDC fish community database collected since 1986. Because

I had to measure the length of each reach by hand, I did it only for species I judged from

other data to be the most likely to meet the thresholds. I calculated fragmentation as the

proportion of isolated reaches. I considered isolated reaches as those with a species

separated by reaches that had been sampled but without finding the species. Isolated

reaches reflected the IUCN definition of a subpopulation. The IUCN considered

occupancy as the number of locations where a species was known to exist. I translated

this as the number of reaches in which a species was known to exist and called this

variable numreach. The IUCN criterion for long-term decline was any decline that was

not just due to population fluctuation. Because I could not discern fluctuation from long-

term decline, I chose change < -40 as a threshold. A decline greater than 40% was a

criterion for vulnerable in the next IUCN threshold and, even if it was only fluctuation, it

was a high level of fluctuation, which would be a threat in itself. If the species had a trait

associated with decline, then I inferred this as significant long-term decline as well.

The third IUCN threshold consisted of a low number of mature individuals plus

high decline or long-term decline plus a weak population structure (Table 2). To estimate

the number of mature individuals, I first calculated the proportion of samples in which a

species was collected within each reach making up its range, averaged over all the

reaches making up its range, using data from the MDC fish community database

collected since 1986. This proportion has been shown to be positively related to local

abundance (Gaston 1996; Hanski and Gyllenberg 1997; Johnson 1998); therefore, I used

29

it as an index of local abundance. I then multiplied this times the total length of stream

making up the range of the species (i.e., rchlength) to obtain popsize, an index of total

number of mature individuals. For high change, I again used the IUCN compounded

values. For long-term decline, I again used change <= -40 or membership in a trait group

associated with decline. The IUCN defined weak population structure as isolated

subpopulations each with very small numbers of mature individuals or all or most mature

individuals in one subpopulation. I estimated both using popsize calculated for each

isolated reach or set of reaches.

The fourth IUCN threshold was based on a very low number of mature

individuals, with criteria based on area occupied and number of locations added to the

vulnerable category (Table 2).

After calculating the modified IUCN categories for each species, I downgraded

those species with populations that extended out of the sampled area. For these species,

there had to be good evidence that the probability of extinction would be less than

expected because of continual immigration into the state (Gardenfors et al. 2001).

I plotted the modified IUCN categories against the state categories of

conservation concern of listed species (Missouri Natural Heritage Program 2003). I then

made recommendations on the conservation status of the small stream fishes of Missouri.

Lastly, I evaluated the adequacy, in terms of sample size and distribution of

samples among reaches, of present data for the purposes of future analyses. I calculated

the average number of samples per reach within the range of each species then multiplied

this times the number of reaches. This value would be close to the number of samples

available in the present to calculate change at some time in the future assuming an even

30

distribution of samples among reaches. Species with low values (<15) would need

additional samples to be made within their range now so that change can be assessed in

the future.

RESULTS

General Patterns in Species Change

Change varied from -100% to 457% for the 91 species with five or more samples

within their ranges (Table 3). Four species showed no change, 49 declined and 38

expanded.

Table 3. Change in species occurrence, 1940s versus 1990s. pres40 = samples in 1940s in which the species was present; all40 = all samples within the range of the species in the 1940s; prop40 = pres40/all40; pres90 = samples in 1990s in which the species was present; all90 = all samples within the range of the species in the 1990s; prop90 = pres90/all90; change = the percent change in proportion. Species pres40 all40 prop40 pres90 all90 prop90 change Arkansas River orangethroat darter 15 16 0.94 14 14 1 7 Banded darter 43 58 0.74 43 59 0.73 -2 Banded sculpin 40 57 0.70 46 58 0.79 13 Bigeye chub 34 37 0.92 19 40 0.48 -48 Bigeye shiner 45 63 0.71 56 70 0.8 12 Bigmouth shiner 39 63 0.62 56 66 0.85 37 Blacknose shiner 7 10 0.7 3 11 0.27 -61 Blackside darter 19 23 0.83 10 22 0.45 -45 Blackspotted topminnow 82 113 0.73 97 114 0.85 17 Blackstripe topminnow 48 75 0.64 51 74 0.7 8 Blacktail shiner 7 12 0.58 10 12 0.83 43 Bleeding shiner 63 73 0.86 67 71 0.94 9 Bluegill 55 181 0.30 165 187 0.88 190 Bluestripe darter 4 13 0.31 11 15 0.73 138 Bluntface shiner 10 10 1 4 9 0.44 -56 Bluntnose darter 14 17 0.82 6 20 0.3 -64 Bluntnose minnow 197 222 0.89 191 223 0.86 -3 Brook silverside 73 105 0.7 83 106 0.78 13 Bullhead minnow 28 39 0.72 32 38 0.84 17 Cardinal shiner 8 9 0.89 8 9 0.89 0

31

Table 3 (continued). Change in species occurrence, 1940s versus 1990s. pres40 = samples in 1940s in which the species was present; all40 = all samples within the range of the species in the 1940s; prop40 = pres40/all40; pres90 = samples in 1990s in which the species was present; all90 = all samples within the range of the species in the 1990s; prop90 = pres90/all90; change = the percent change in proportion, 1940s to 1990s. Species pres40 all40 prop40 pres90 all90 prop90 change Central stoneroller 174 203 0.86 170 201 0.85 -1 Common shiner 14 26 0.54 24 32 0.75 39 Creek chub 100 158 0.63 126 162 0.78 23 Creek chubsucker 14 16 0.88 4 15 0.27 -70 Duskystripe shiner 16 16 1 15 15 1 0 Eastern redfin shiner 37 48 0.77 33 49 0.67 -13 Emerald shiner 27 47 0.57 34 46 0.74 29 Fathead minnow 88 96 0.92 46 89 0.52 -44 Freckled madtom 6 7 0.86 1 6 0.17 -81 Ghost shiner 26 30 0.87 12 32 0.38 -57 Gilt darter 12 15 0.8 5 14 0.36 -55 Golden shiner 46 68 0.68 37 66 0.56 -17 Gravel chub 20 28 0.71 12 29 0.41 -42 Greenside darter 70 87 0.80 73 85 0.86 7 Green sunfish 192 228 0.84 169 224 0.75 -10 Hornyhead chub 87 88 0.99 64 88 0.73 -26 Johnny darter 86 116 0.74 90 118 0.76 3 Largescale stoneroller 64 84 0.76 75 85 0.88 16 Longear sunfish 118 141 0.84 124 139 0.89 7 Meramec River saddled darter 10 14 0.71 10 14 0.71 0 Mimic shiner 13 21 0.62 14 23 0.61 -2 Mississippi silvery minnow 8 10 0.8 4 10 0.4 -50 Missouri saddled darter 19 21 0.90 12 22 0.55 -40 Mottled/Ozark sculpin 18 42 0.43 48 51 0.94 120 Northern logperch 5 13 0.38 10 13 0.77 100 Northern orangethroat darter 95 133 0.71 127 136 0.93 31 Northern studfish 71 86 0.83 79 91 0.87 5 Ohio logperch 4 12 0.33 6 11 0.55 64 Orangespotted sunfish 132 142 0.93 61 134 0.46 -51 Ozark chub 4 7 0.57 2 6 0.33 -42 Ozark logperch 61 82 0.74 57 91 0.63 -16 Ozark madtom 4 13 0.31 11 15 0.73 138 Ozark minnow 77 88 0.88 79 89 0.89 1 Ozark shiner 7 9 0.78 3 10 0.3 -61 Pallid shiner 9 11 0.82 0 10 0 -100 Peppered chub 5 10 0.5 8 8 1 100 Plains minnow 19 20 0.95 2 15 0.13 -86 Plains topminnow 10 16 0.62 10 16 0.62 0 Pugnose minnow 5 9 0.56 4 10 0.4 -28 Rainbow darter 70 86 0.81 87 91 0.96 18 Red shiner 167 172 0.97 126 164 0.77 -21 Redspot chub 9 9 1 7 9 0.78 -22

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Table 3 (continued). Change in species occurrence, 1940s versus 1990s. pres40 = samples in 1940s in which the species was present; all40 = all samples within the range of the species in the 1940s; prop40 = pres40/all40; pres90 = samples in 1990s in which the species was present; all90 = all samples within the range of the species in the 1990s; prop90 = pres90/all90; change = the percent change in proportion, 1940s to 1990s. Species pres40 all40 prop40 pres90 all90 prop90 change Redspotted sunfish 6 8 0.75 2 7 0.29 -62 Ribbon shiner 9 9 1 3 7 0.43 -57 Rosyface shiner 73 87 0.84 57 88 0.65 -23 Sand shiner 135 156 0.87 113 153 0.74 -15 Silver chub 18 25 0.72 6 20 0.3 -58 Slenderhead darter 42 49 0.86 28 51 0.55 -36 Slender madtom 56 102 0.55 77 108 0.71 30 Slough darter 7 8 0.88 6 11 0.55 -38 Southern redbelly dace 19 35 0.54 25 39 0.64 18 Speckled darter 5 9 0.56 7 10 0.7 26 Spotfin shiner 22 24 0.92 9 22 0.41 -55 Steelcolor shiner 13 20 0.65 12 21 0.57 -12 Stippled darter 21 37 0.57 15 33 0.45 -20 Stonecat 14 28 0.5 19 32 0.59 19 Striped fantail darter 60 108 0.56 93 109 0.85 54 Striped shiner 52 74 0.70 75 87 0.86 23 Suckermouth minnow 111 128 0.87 78 127 0.61 -29 Tadpole madtom 22 30 0.73 12 28 0.43 -42 Telescope shiner 14 17 0.82 14 18 0.78 -6 Topeka shiner 12 14 0.86 1 14 0.07 -92 Trout-perch 9 11 0.82 1 12 0.08 -90 Warmouth 8 17 0.47 14 18 0.78 65 Wedgespot shiner 27 36 0.75 27 39 0.69 -8 Weed shiner 9 9 1 0 5 0 -100 Western mosquitofish 17 104 0.16 111 122 0.91 457 Western redfin shiner 80 96 0.83 64 92 0.7 -17 White River orangethroat darter 6 14 0.43 12 14 0.86 100 Whitetail shiner 12 13 0.92 5 13 0.38 -58 Yoke darter 10 13 0.77 11 14 0.79 2

Decline was greatest in the northern Ozarks and the White River basin (Figure 2).

Expansion was greatest in the southern and western plains (Figure 3).

33

34

35

From examination of distribution maps of individual species (Appendix Figures

Arkansas River Orangethroat Darter – Yoke Darter), I saw regions of decline in 45

species (Table 4) and of expansion in 33 species (Table 5). One unexpected pattern was

the decline of plains species from the Ozarks, including blacknose shiner, blackstripe

topminnow, eastern redfin shiner, johnny darter, orangespotted sunfish, red shiner, sand

shiner, slenderhead darter, suckermouth minnow, and western redfin shiner. Ten of the 18

species that showed decline in the Ozarks were plains species. Another surprising pattern

was the expansion of Ozark species into the plains, including bigeye shiner, blackspotted

topminnow, bluntnose minnow, brook silverside, central stoneroller, gravel chub, longear

sunfish, northern orangethroat darter, northern studfish, Ozark logperch, slender madtom,

steelcolor shiner, striped fantail darter, and striped shiner. Ozark species made up 14 of

the 26 species that showed expansion in the plains. Thirteen species showed decline in

one part of their range and expansion in another part. Species that declined out of the

Ozarks and expanded into the plains were blackstripe topminnow, bluntnose minnow,

gravel chub, johnny darter, mimic shiner, Ozark logperch, slenderhead darter, and

steelcolor shiner. Six species declined in the lowlands while none expanded in it. Large

river species declined in the White River basin, which is not surprising given the

impoundment of the entire length of the mainstem White River in Missouri.

36

Table 4. Species showing regional decline. Lowlands Ozarks White R. Plains ----------------- ----------------- N W S E N W S E Bigeye chub X X X Blacknose shiner X X Blackside darter X Blackstripe topminnow X X X Bluntface shiner X Bluntnose darter X Bluntnose minnow X X X X X X Creek chubsucker X X Eastern redfin shiner X Fathead minnow X X X X Freckled madtom X X Ghost shiner X X X Gilt darter X X X Golden shiner X Gravel chub X Hornyhead chub X X X X X X Johnny darter X Largescale stoneroller X Mimic shiner X X Mississippi silvery minnow X X Missouri saddled darter X Orangespotted sunfish X X X X X X X Ozark logperch X X X Ozark shiner X Pallid shiner X X Plains minnow X X X Red shiner X X X Redspotted sunfish X Ribbon shiner X Rosyface shiner X Sand shiner X X X Silver chub X X X X Slenderhead darter X X X Southern redbelly dace X Spotfin shiner X X Steelcolor shiner X Suckermouth minnow X X X X Tadpole madtom X X Topeka shiner X X X Trout-perch X X Wedgespot shiner X Weed shiner X Western redfin shiner X X Whitetail shiner X

37

Table 5. Species showing regional expansion. Lowlands Ozarks White R. Plains ----------------- ----------------- N W S E N W S E Bigeye shiner X X Bigmouth shiner X X Blackspotted topminnow X Blackstripe topminnow X X Bluegill X X X X X X X X Bluestripe darter X Bluntnose minnow X X Brook silverside X X Central stoneroller X X Creek chub X X X X Eastern redfin shiner X X Emerald shiner X X Fathead minnow X X Golden shiner X Gravel chub X Johnny darter X Largescale stoneroller X X Longear sunfish X Mimic shiner X Mottled/Ozark sculpin X X X X X Northern logperch X Northern orangethroat darter X X X Northern studfish X X Ozark logperch X X Ozark madtom X X Slenderhead darter X Slender madtom X X X Southern redbelly dace X X X Steelcolor shiner X Striped fantail darter X X X X Striped shiner X X X Western mosquitofish X X X X X X X X White River orangethroat darter X

There were relationships between and species traits. The number of basins in

which a species was known to occur in Missouri was significantly related to (P =

0.0192, N = 90) but the proportion of the variation explained by a straight line was very

low (R2 = 0.06, Figure 4). Reproductive groups showed no relation to (Figure 5). A

38

majority (33 of 48 species, 69%) of the Cyprinidae declined (Figure 6). Three of four

herbivores declined (75%, Figure 7). Thirteen of 19 plains species declined (68%, Figure

8). For stream type (Figure 9), declines occurred in species characteristic of clear lowland

ditches (six of six species, 100%), large Ozark rivers (14 of 17 species, 82%), plains

headwaters (three of four species, 75%), and plains small and large rivers combined

(seven of eight species, 88%). Expansion occurred in species characteristic of lowland

standing waters (three of four species, 75%), Ozark creeks (seven of 10 species, 70%),

and small Ozark rivers (11 of 15 species, 73%). Species in which Missouri was at the

western or northwestern edge of the range declined (four of five [80%] and 11 of 14

[79%] species respectively, Figure 10). Species in which Missouri was at the eastern or

northeastern edge of the range also declined (three of four species, 75%). Of the species

that declined and the trait categories associated with decline, Cyprinidae had 15 unique

species, small plains rivers and large Ozark rivers had three unique species each,

northwestern edge of the range had two unique species, and plains headwaters, large

plains rivers, and clear lowland ditches had one unique species each. Herbivore, plains,

small plains rivers, western, eastern, and northeastern edges of the range had no unique

species. Altogether, the trait categories with unique species accounted for 47 of the 49

declined species (96%). If the common species (those for which change could be

calculated) represent the same distribution of traits as the rare species, then any rare

species with any of the seven traits associated with decline likely would have declined as

well; conversely, any rare species that did not fit one of the seven trait categories

associated with decline likely would not have declined. The three trait categories

associated with expansion were mutually exclusive, so would have no common species

39

by definition. They accounted for 21 of the 38 expanded species (55%). This much lower

percentage meant that expansion was not as predictable based on species traits as was

decline.

40

41

42

43

44

45

46

Conservation Status of Species

The number of reaches in which a species had been recently collected (numreach)

varied from zero for the extirpated species pallid shiner to 905 for green sunfish (Table

6). The proportion of samples with a species within the reaches where it had been

recently collected (proportion) varied from zero for pallid shiner and longnose darter to

1.0 for spring cavefish. Although spring cavefish was found only in one small spring, it

was always found there. Longnose darter was last seen in the state in 1987 and the

observation was not part of a community sample. All community samples within the

reach where it was seen have been negative for this species.

Table 6. Extinction correlates and sample adequacy. Numreach = the number of reaches in which a species has been found between 1986 and 2001. Proportion = the proportion of samples with the species within these reaches. Rchlength = the total length of these reaches in km. Fragmentation = the proportion of reaches that are isolated. Baseline = an estimate of the number of samples available as a baseline for calculating change in the future. Species Numreach Proportion Rchlength Fragmentation Baseline Alabama shad 10 0.35 51 Arkansas darter 61 0.84 159 Arkansas River orangethroat darter 97 0.95 218 Arkansas saddled darter 2 0.24 44.3 1.00 10 Banded pigmy sunfish 40 0.80 119 Banded sculpin 202 0.84 437 Bantam sunfish 13 0.81 0.23 31 Barred fantail darter 25 0.88 35 Banded darter 125 0.82 354 Bigeye chub 67 0.78 157 Bigeye shiner 213 0.85 468 Bigmouth shiner 317 0.92 544 Blacknose shiner 18 0.82 49 Blackside darter 53 0.65 168 Blackspotted topminnow 392 0.91 765 Blackstripe topminnow 188 0.86 372 Blacktail shiner 59 0.87 166 Bleeding shiner 274 0.96 519 Bluegill 781 0.88 1474 Bluestripe darter 17 0.69 66 Bluntface shiner 10 0.81 28 Bluntnose darter 52 0.75 147 Bluntnose minnow 727 0.93 1375 Brassy minnow 13 0.92 28

47

Table 6 (continued). Extinction correlates and sample adequacy. Numreach = the number of reaches in which a species has been found between 1986 and 2001. Proportion = the proportion of samples with the species within these reaches. Rchlength = the total length of these reaches in km. Fragmentation = the proportion of reaches that are isolated. Baseline = an estimate of the number of samples available as a baseline for calculating change in the future. Species Numreach Proportion Rchlength Fragmentation Baseline Brindled madtom 13 0.60 62 Brook darter 24 0.90 55 Brook silverside 281 0.84 658 Bullhead minnow 93 0.80 269 Cardinal shiner 51 0.92 104 Central mudminnow 2 0.67 1.5 1.00 4 Central stoneroller 827 0.93 1459 Channel darter 10 0.53 54 Checkered madtom 7 0.34 250.0 0.71 26 Common shiner 122 0.92 200 Creek chub 743 0.93 1266 Creek chubsucker 59 0.83 120 Crystal darter 6 0.41 362.9 0.50 58 Current darter 20 0.85 42 Current River saddled darter 5 0.85 161.9 0.30 10 Cypress darter 58 0.88 141 Cypress minnow 2 0.62 145.7 1.00 18 Dollar sunfish 10 0.90 36.6 0.33 12 Dusky darter 25 0.75 104 Duskystripe shiner 50 0.99 90 Eastern redfin shiner 192 0.87 371 Eastern slim minnow 1 0.23 84.0 1.00 22 Emerald shiner 94 0.74 255 Fathead minnow 286 0.83 543 Flier 13 0.66 52 Freckled madtom 19 0.53 100 Ghost shiner 19 0.75 41 Gilt darter 30 0.69 120 Golden shiner 329 0.80 682 Golden topminnow 5 0.65 42.5 0.20 22 Goldstripe darter 11 0.83 5.7 0.18 21 Gravel chub 39 0.70 123 Green sunfish 905 0.89 1665 Greenside darter 226 0.83 559 Harlequin darter 8 0.64 405.2 0.50 62 Hornyhead chub 202 0.90 395 Ironcolor shiner 7 0.95 63.8 0.25 16 Johnny darter 408 0.87 806 Lake chubsucker 10 0.71 40 Largescale stoneroller 284 0.92 555 Least darter 30 0.62 101 Longear sunfish 476 0.92 937 Longnose darter 1 0.00 23.2 1.00 2 Meramec River saddled darter 20 0.95 48 Mimic shiner 50 0.73 167 Mississippi silvery minnow 22 0.77 86 Missouri saddled darter 45 0.85 121 Mottled sculpin 170 0.87 115 Mountain madtom 1 0.23 84.0 1.00 22 Mud darter 13 0.63 67

48

Table 6 (continued). Extinction correlates and sample adequacy. Numreach = the number of reaches in which a species has been found between 1986 and 2001. Proportion = the proportion of samples with the species within these reaches. Rchlength = the total length of these reaches in km. Fragmentation = the proportion of reaches that are isolated. Baseline = an estimate of the number of samples available as a baseline for calculating change in the future. Species Numreach Proportion Rchlength Fragmentation Baseline Neosho madtom 1 0.71 12.8 1.00 8 Niangua darter 16 0.38 0.44 34 Northern logperch 22 0.69 49 Northern orangethroat darter 498 0.94 844 Northern studfish 277 0.92 544 Ohio logperch 37 0.73 130 Orangespotted sunfish 227 0.76 536 Ozark chub 20 0.72 69 Ozark madtom 44 0.75 119 Ozark minnow 291 0.93 572 Ozark logperch 190 0.78 412 Ozark sculpin * * 197 Ozark shiner 13 0.91 27 Pallid shiner 0 0.00 0.0 1.00 Peppered chub 20 0.79 38 Pirate perch 57 0.81 144 Plains killifish 4 0.67 77.6 0.75 16 Plains minnow 7 0.64 208.2 0.14 17 Plains orangethroat darter 24 0.86 46 Plains topminnow 33 0.77 76 Pugnose minnow 33 0.62 129 Rainbow darter 298 0.94 570 Redear sunfish 41 0.52 135 Redfin darter 3 0.60 59.0 0.33 23 Red shiner 509 0.94 907 Redspot chub 33 0.90 64 Redspotted sunfish 55 0.75 150 Ribbon shiner 29 0.78 109 River darter 13 0.64 55 Rosyface shiner 205 0.82 487 Sabine shiner 1 0.64 84.0 1.00 22 Saddleback darter 11 0.55 60 Sand shiner 394 0.92 738 Scaly sand darter 15 0.67 68 Silver chub 16 0.67 36 Silverjaw minnow 17 0.84 30 Slenderhead darter 72 0.70 249 Slender madtom 280 0.78 620 Slough darter 80 0.80 206 Southern redbelly dace 207 0.85 374 Speckled darter 26 0.66 110 Spotfin shiner 43 0.67 156 Spring cavefish 1 1.00 0.4 1.00 1 Stargazing darter 2 0.19 127.1 1.00 26 Starhead topminnow 17 0.82 0.18 41 Steelcolor shiner 52 0.91 97 Stippled darter 123 0.74 316 Stonecat 54 0.59 181 Striped fantail darter 377 0.87 736 Striped shiner 233 0.91 458

49

Table 6 (continued). Extinction correlates and sample adequacy. Numreach = the number of reaches in which a species has been found between 1986 and 2001. Proportion = the proportion of samples with the species within these reaches. Rchlength = the total length of these reaches in km. Fragmentation = the proportion of reaches that are isolated. Baseline = an estimate of the number of samples available as a baseline for calculating change in the future. Species Numreach Proportion Rchlength Fragmentation Baseline Suckermouth minnow 241 0.83 504 Swamp darter 6 0.66 41.3 0.33 18 Tadpole madtom 58 0.68 158 Taillight shiner 6 0.47 196.0 0.33 44 Telescope shiner 77 0.92 141 Topeka shiner 19 0.87 27.0 0.27 42 Trout-perch 15 0.57 51 Warmouth 113 0.80 283 Wedgespot shiner 90 0.83 246 Weed shiner 24 0.81 112 Western mosquitofish 409 0.85 889 Western redfin shiner 273 0.86 540 Western sand darter 13 0.35 80 Western silvery minnow 1 0.25 17.4 1.00 4 Western slim minnow 8 0.61 232.0 0.11 26 Whitetail shiner 30 0.83 94 White River fantail darter 13 0.68 34 White River orangethroat darter 42 0.86 82 Yoke darter 14 0.84 35 *Combined with mottled sculpin.

I calculated the total length of the reaches in which a species had been collected

recently (rchlength) for the 27 species that I estimated would have the shortest lengths.

This varied from 0.0 km for pallid shiner and 0.4 km for spring cavefish to 405.2 km for

harlequin darter. Isolation of populations (fragmentation) varied from 0.11 for eastern

slim minnow to 1.0 for 12 species. Again, I calculated fragmentation only for species in

few reaches and other species that I judged beforehand to have a potentially high value.

Pallid shiner had a value of 1.0 because it was extirpated from the state. Seven other

species had a value of 1.0 because they were found in only one reach. Seven species

found in more than one reach had fragmentation values >= 0.5. I analyzed 26 species for

weak population structure and found popsize < 5 in all subpopulations of central

mudminnow and popsize < 25 in all subpopulations of Arkansas saddled darter, swamp

50

darter, goldstripe darter, redfin darter, golden topminnow, plains killifish, dollar sunfish,

taillight shiner, and stargazing darter. Swamp darter had 100% of its total popsize in one

subpopulation, as did all species with numreach = 1 (Table 6). Goldstripe darter had 96%

of its total popsize in one subpopulation, and plains killifish had 92% of its total popsize

in one subpopulation.

One or more of the modified IUCN thresholds were met by 23 species. Five of

these species were downgraded one step because the population extended outside of the

sampled region. Pflieger (1997) reported large numbers of stargazing darters in the

Current River just south of the border in Arkansas. If the reach south of the border is

considered a separate reach, fragmentation for this species decreases to 0.33 and

population structure would improve. Likewise, large numbers just south of the border

would offset the low proportion of sites occupied on the Missouri side of the Current

River and increase the number of reaches and length of stream occupied. They are also

present in the Black River, which was excluded from this analysis. So, stargazing darter

would be downgraded from vulnerable to off the list. The population centers of western

silvery minnow and plains minnow are in the Missouri River. This would downgrade

western silvery minnow from highly endangered to endangered and plains minnow to off

the list. Most of the population of Neosho madtom is just across the border in Kansas,

therefore, this species should be downgraded from endangered to vulnerable. The weed

shiner is widespread and abundant in the mainstems of the Black and St. Francis Rivers

in Missouri which were not included in the 1940s samples. It should be downgraded to

endangered. Even though it is presently abundant, it should be monitored carefully

because of its historically extremely high rate of decline. In summary, four species met

51

the criteria for highly endangered: central mudminnow, longnose darter, pallid shiner,

and spring cavefish. Eight species met the criteria for endangered: Arkansas saddled

darter, eastern slim minnow, golden topminnow, goldstripe darter, mountain madtom,

redfin darter, Topeka shiner, weed shiner, and western silvery minnow. Eight species met

the criteria for vulnerable: Current River saddled darter, cypress minnow, ironcolor

shiner, Neosho madtom, plains killifish, Sabine shiner, taillight shiner, and trout-perch.

Agreement between the modified IUCN categories calculated here and the

existing state ranks was fairly strong (Figure 11). Between the state ranks of SX

(extirpated) and S1? (S1 but questionable), 15 of the19 state-listed species met the

modified IUCN criteria. Between the state ranks of S2 (imperiled) and SU (status

unknown), three of the 29 state-listed species met the modified IUCN criteria. In general,

the IUCN criteria encompassed only the most endangered ranks of the state list. Three

state-unlisted species, Arkansas saddled darter, Current River saddled darter, and weed

shiner, met the modified IUCN criteria. Four species listed as state endangered (the most

critical level of endangerment that can be assigned at the state level), crystal darter,

harlequin darter, Niangua darter, and swamp darter did not meet the modified IUCN

criteria.

52

Eight species did not have adequate baseline sample sizes within their ranges to

be able to calculate future change (Table 6). Two of these, central mudminnow and

spring cavefish, were found in such small habitats that making multiple community

samples would be impractical. The western silvery minnow was collected only once and

was probably a stray from the Missouri River. Further sampling for this species in the one

reach where it was found would probably not be useful. The Neosho madtom is a

federally threatened species that is being monitored intensively; therefore, probably does

not need to be monitored with community samples within its range. The other four

species, Arkansas saddled darter, dollar sunfish, longnose darter, and White River

saddled darter, and must be sampled now if adequate estimates of change are to be

calculated in the future.

53

DISCUSSION

General Patterns in Species Change

Greatest expansion of species was in the southern and western plains. Over half of

the species were Ozark species. Greatest decline was in the northern Ozarks. Over half of

these species were plains species. Membership in the family Cyprinidae was the most

important trait associated with decline. Species characteristic of small Ozark rivers and

creeks generally expanded.

The first explanation for these patterns is sampling bias. There was relatively little

standardization in the samples; only total time spent sampling or total number of

individuals. Seine sizes were different. Harry made almost all the samples in the 1940s,

which should help the consistency of sampling, but samples in the 1990s were made by

many biologists.

The pattern of expansion in the southern and western plains (over half of these

species characteristic of the Ozarks) and decline from the Ozarks (over half of these

species characteristic of the plains) was counter-intuitive. Unexpected results like this

make one wonder about the robustness of the data. There is a pressing need, therefore, to

be sure that the pattern is not due to sampling bias.

In the 1940s, the southern and western plains were sampled by Harry. In the

1990s, 49 of 58 samples were made by four biologists: Bruenderman, Pflieger, Bayless,

and Winston. One way an illusion of expansion could have been created is if the 1990s

samplers did a better job than Harry. The 1990s samplers had advantages, even given the

same effort as Harry. For one, they had Harry’s data as a benchmark. They would know

what species to expect at the site and in the vicinity and could focus on finding those that

54

were not easily caught. A competitive or professional attitude could have pushed the

samplers to do better than Harry. The 1990s samplers probably had a better knowledge of

the fish and their habitats, given books like The Fishes of Missouri. Harry was a young

graduate student at the time he made the samples; most of the 1990s samplers were

experienced fisheries biologists. Supporting this contention, a t-test on species richness of

sample pairs in the south and east plains was significant (P<0.0001, N=55). Species

richness of samples was 2.618 species lower in the 1940s on average. Effort in terms of

sample time did not differ (P=0.1234, N=55) as expected from the way the data were put

together. Results did not change with log transformation of the data.

However, there are several reasons to think that sampling bias was not the reason

for the pattern of expansion. First, the species that expanded were collected by Harry in

other places, so we know that he had experience collecting them. He sampled in Missouri

from June through September in 1940 and in July and August 1941 (Figure 12). These

sample times extended through most of the summer of two years, giving confidence that

local, short-term weather events did not have large effects on the results. Annual mean

stream flow in 1940 and 1941 was at or below average (Figure 13), so long-term high

water does not seem to be the explanation. If Ozark species were rare in the southern and

western plains both in the 1940s and 1990s, then better sampling in the 1990s might have

captured them more often. However, this explanation is contradicted by the relatively

high abundances of Ozark species in the plains in the 1990s (Table 7). Only northern

studfish was rare in the 1990s samples. Lastly, the expansion of species was consistent

and region wide.

55

56

57

Table 7. Abundance of Ozark species in 1990s samples where they showed expansion into the southern and western plains. N = number of samples; mean = mean abundance; SD = standard deviation of abundance; range = range of abundance. Species N mean SD Range Blackspotted topminnow 4 20.5 20.3 1-40 Bluntnose minnow 7 26.9 44.1 2-121 Brook silverside 10 11.7 12.6 1-39 Central stoneroller 6 21.8 22.4 1-59 Gravel chub 3 3.7 2.3 1-5 Longear sunfish 9 11.8 17.6 1-57 Northern orangethroat darter 9 11.8 10.8 1-30 Northern studfish 1 1.0 Ozark logperch 7 3.1 2.7 1-7 Slender madtom 5 5.6 4.0 1-10 Striped fantail darter 6 5.3 3.7 1-10

If Harry did a better job of sampling than Bruenderman, Pflieger, and the others,

then the pattern of decline in the northern Ozarks might be an artifact of sampling. A t-

test on species richness of sample pairs in the northern Ozarks was significant (P=0.0059,

N=90). Species richness of samples was 1.3556 species higher in the 1940s on average.

Effort in terms of sample time did not differ (P=0.0964, N=90). Results did not change

with log transformation of the data. However, we know that Bruenderman and Pflieger

made adequate community samples. They sampled all habitats extensively. Probably 90%

or more of the small fish species in a reach were sampled.

Although standardization was weak, the strong patterns do not seem to be artifacts

of biased sampling.

There were 64 trait categories represented in the species for which change could

be calculated. Seven of these accounted for 96% of the species that declined. What is the

significance that most Cyprinidae declined but not Ictaluridae, Centrarchidae, or

Percidae; that most plains species declined but not Ozark species; that most Ozark large-

58

river species declined but other Ozark species expanded; that lowland clear-ditch and

natural river species declined but standing water species expanded; that species with

western and eastern range edges in Missouri declined but not those with northern and

southern range edges?

In the 1800s, the Ozark region was the center of a large timber industry, but

profitable virgin timber harvest was exhausted by about 1915 (Rafferty 1980). A large

human population remained in the Ozarks, however, relying heavily on subsistence

hunting and fishing. Open-range grazing was practiced on the cutover lands, and regular

burning was used to increase forage. Between 1920 and 1960, riparian vegetation was

widely destroyed in small Ozark valleys due to concentration of livestock near water in

the valley bottoms (Jacobson and Primm 1997). This encouraged headward migration of

channels and released gravel from storage in the small valleys. The gravel moved

downstream and filled pools and channels. Downstream channels were shallower in the

1990s than they were in the 1940s. This could be part of the explanation for the decline in

the Ozarks of large river species and the expansion of small-river and creek species.

However, it does not seem to explain why plains species declined from the Ozarks.

In the plains region of Missouri, deeply plowed fields were made possible with

the general adoption of the moldboard plow during the latter half of the 19th century.

From then up through the early 20th century were times of intensive land drainage, stream

channelization, and rapid increase in row cropping. The relative rate of both

environmental and faunal change probably has declined since about 1940 (Larimore and

Smith 1963; King 1973; Menzel et al. 1984; Cross and Collins 1985). However, the

extent of plowed land is one of the most obvious differences between the Ozarks and the

59

plains, and there is no doubt that plowing increases sedimentation of streams (Meade et

al. 1990). This explanation for the greater relative decline of plains species compared to

Ozark species is supported by a partitioning of simple lithophilous spawners into plains

and Ozark species. This spawning category is considered the most sensitive to

sedimentation (Berkman and Rabeni 1987; Rabeni and Smale 1995). In the plains, seven

of eight species declined; in the Ozarks, 13 of 25 species declined (I included species

known to spawn on the nests of other species, such as Ozark minnow, Topeka shiner, and

western redfin shiner in this count).

Predation is another potential explanation. In the early 1900’s, Canada geese,

whitetail deer, and wild turkey were either extirpated or very rare in the state due to

intensive subsistence hunting and no regulation. These species are now so abundant that

they are considered nuisances in many places. It is reasonable to expect the same for

large fishes. Not only has management of wild populations improved, but there are also

widespread stocking programs in public and private waters. Larimore and Bayley (1996)

reported increases in large piscivorous fish in Champaign County, Illinois since 1959.

Predation may explain many of the patterns found in this analysis. Small, lowland

standing-water species expanded. These would be pre-adapted to living with large

predators such as largemouth bass (Micropterus salmoides). The Cyprinidae, which

strongly declined, have been found to be especially susceptible to increased predation

(Whittier et al. 1997) and likely to be extirpated (Angermeier 1995). Loss of minnows

has been associated with farm ponds, impoundments, and largemouth bass (Schrank et al.

2001; Jackson 2002; Mammoliti 2002; Winston 2002). Farm ponds are often perched

high in the watershed and are a source of predators into headwater streams. This would

60

explain the decline of plains species even in the headwaters. However, predation does not

seem to explain the expansion of Ozark species into the plains and the loss of plains

species from the Ozarks.

Another explanation is that species’ range sizes tend to be positively correlated

with their environmental tolerances (Scott and Helfman 2001). Thus, declining or

extirpated species would tend to have small geographic ranges (Angermeier 1995). This

may explain the pattern I found between change and the number of basins in which a

species was known to occur, but it does not seem to explain any of the other patterns.

Warming from climate change has been of intense recent interest (e.g., Wood and

McDonald 1997; Hill et al. 1999; Hellberg et al. 2001). I found no evidence for this in

this study. Plains fishes declined out of the Ozarks. One would expect the opposite

because plains fish are more tolerant of higher temperatures. Furthermore, the cool-water

sculpins expanded as a group, as did the spring-associated southern redbelly dace.

Species with northern or southern range edges in Missouri also did not change as a group.

The Missouri River has become less turbid since the 1940s with the construction

of multiple large impoundments between Montana and Nebraska. Fishes characteristic of

clear water have been expanding their ranges into the Missouri River and its plains

tributaries (Hesse 1987; Pflieger and Grace 1987; Galat et al. 1996). For example, the

bullhead minnow, a small species characteristic of the much clearer Mississippi River,

has become abundant in the Missouri River and its plains tributaries in the last 10 years

(MDC fish community database, unpublished). This could be part of the explanation for

the pattern of expansion in the southern and western plains. However, the Missouri River

still seems a formidable barrier to small Ozark species (see Table 7). Furthermore, the

61

area of expansion also includes the western Osage River, which is disconnected from the

Missouri River by two large dams. Seven Ozark species have expanded in the western

Osage basin: central stoneroller, creek chub, northern orangethroat darter, Ozark

logperch, slenderhead darter, slender madtom, and striped fantail darter. Missouri River

changes probably explain the decline of plains minnow and western silvery minnow and,

possibly, silver chub.

The pattern of decline in the northern Ozarks might also be attributable to the

major changes in habitat and fauna in the Missouri River. However, most of the northern

Ozarks was not directly connected to the Missouri River. In the 1940s, the Osage River

tributaries were disconnected from the Missouri River by Bagenal Dam. The Meramec

River drains to the Mississippi River, and the Spring River drains to the Arkansas River.

Three small, plains species (ghost shiner, red shiner, sand shiner) increased in distribution

in the Missouri River from the 1940s to the 1990s (Pflieger and Grace 1987), opposite of

the pattern found in the northern Ozarks.

Another explanation is drought. Water levels were extremely low in the 1930s for

at least eight years before the sampling was done (Figure 13). This could explain the

phenomenon of plains species widespread in the northern Ozarks if water temperatures

were higher due to less spring influence. In Kansas, the drought caused complete fish

kills in many streams and, in Missouri, six rescue crews were employed to salvage fish

from shrinking pools (James 1934). One might expect that Ozark species at the edge of

their range in the southern and western plains would be more susceptible to this type of

disturbance than plains species. At the time that Harry sampled, the aquatic community

might not have fully recovered from the disturbance. This could explain the expansion of

62

Ozark species into the southern and western plains.

Lastly, a variety of human activities could have produced geomorphic conditions

that extended Ozark-like stream conditions into the plains. Examples include channel

downcutting from enhanced runoff and headcuts from gravel mining and channelization.

The overlying fine sediments could have been removed, leaving bedrock and large rocks

that are not easily moved, and making better habitat for Ozark species. Forests more

characteristic of the Ozarks increased in area in the plains of Missouri over the 20th

century (e.g., Hrabik 1992) and may have made streams more Ozark-like. Compaction of

soils by intensive livestock grazing and establishment of fescue monocultures has

decreased infiltration, drying up headwater streams in the plains, possibly making them

more like headwater Ozark streams.

The findings of the present study were similar to those of King (1973) in Boone

County, Iowa between 1947 and 1972, but dissimilar to those of Larimore and Bayley

(1996) in Champaign County, Illinois between 1928 and 1988. The four species that King

(1973) noted as expanding also expanded in the present study in the region bordering

Iowa. The other common species he analyzed showed no change. As for Larimore and

Bayley (1996) and the present study, six species expanded in both studies, nine species

expanded in one study and declined in the other, and five species declined in both studies.

The results reported here represent two snapshots in time in a particular region. A

sample size of two in a time series does not allow one to differentiate between trends and

temporary changes. If something like drought is responsible for some of the patterns, then

these results show that large shifts in range for many species can occur in a relatively

short time.

63

Except for the White River basin, the rest of the state did not show as strong a

pattern. For example, 13 species declined from the east plains and 12 species expanded,

and five species declined from the north plains and five species expanded. The types of

species that changed in these two regions were mostly the same plains species that

changed in the south and west plains. A possible pattern can be seen in the seven, mostly

clear-ditch, species that declined from the lowlands (no species expanded into the

lowlands). This decline seems to have been concentrated in the western part of the

Bootheel of Missouri. The eastern Bootheel has a stronger groundwater influence from

the Mississippi River, creating more clear-ditch habitat. This type habitat may have

declined in the west.

Conservation Status of Species

Progress in listing species at the state level should tend toward greater objectivity.

This includes logical criteria based on stronger theory, better data, and clearer

documentation. The biggest obstacle is that there are many species and not enough

resources for adequate research. I have applied here a simplification of the IUCN criteria

based on presence/absence in community samples. The Missouri Species of Conservation

Concern Checklist (Missouri Natural Heritage Program 2003) is based on an element

state ranking database that contains the documentation for the criteria used to list a

species. These criteria are similar to the IUCN criteria, such as the estimated number of

element occurrences, abundance, range, and trend. There are also comments on each of

these and additional information such as degree of protection and types of threats. In my

experience, these data are used more for reference than as thresholds. The main source

64

for making listing recommendations is consensus of expert opinion. Although the criteria

are documented, the discussion made in the process of getting to consensus is not.

Implementation of the IUCN criteria, even partially or in a simplified form as in this

study, can provide two avenues for greater objectivity. First, implementation of the IUCN

criteria would move the listing procedure towards more reliance on the data and less on

expert opinion. This would make the listing procedure more defensible and easier to

improve. It would provide clearer goals for recovery of a species. Second, the

combination of criteria into thresholds based on population biology theory would seem to

be an improvement over giving all criteria equal and independent weight.

As far as specific recommendations, the IUCN recommends not downlisting a

species until another survey at least five years later corroborates the downlisting

recommendation. Therefore, the four state-endangered species that did not meet the

modified IUCN criteria, crystal darter, swamp darter, harlequin darter, and Niangua

darter, should not be immediately downlisted. The three unlisted species that met the

modified IUCN criteria, Arkansas saddled darter, Current River saddled darter, and weed

shiner, should be listed.

The IUCN criteria evidently do not encompass the range of the element state

ranking criteria. The IUCN does provide another category of threat, near threatened,

which they define as “close to qualifying for or is likely to qualify for a threatened

category in the near future.” This category seems to encompass the state ranks of S2

(imperiled) through S4 (of long-term concern) and S? (status unknown).

There is, of course, plenty of room for improvement in how the community

samples are made. One big improvement would be to standardize the way the samples are

65

made. This would reduce variability in the criteria estimates.

The simplifications I had to make can all be made more robust. At some time, it

may become feasible to estimate absolute numbers within a certain area; or, if

presence/absence is used, a more precise relationship between distribution and abundance

may be developed. Mature individuals and juveniles could be differentiated. The

estimates of range based on stream order might be improved by including other habitat

measures. Seasonal changes in species distribution, such as spawning migrations or

dispersal of young into habitats where survival is relatively low, may need to be

accounted for (Fausch et al. 2002; M. D. Combes and M. R. Winston, manuscript in

review).

Periodic community samples may be the most cost-effective way to monitor

species, ecosystems, and landscapes (Noss 1987; Kareiva and Wennergren 1995). As

shown in this analysis, community samples can provide data for listing criteria for

individual species. Listing criteria, in turn, are essential for prioritizing management

resources for the preservation of species diversity. Common but economically valuable

species, such as sport fish, are also caught in community samples, allowing monitoring of

the fisheries resource. This analysis also showed that community samples can illuminate

spatial patterns on the landscape. Monitoring these patterns over time can provide

managers with insight into the importance of various natural and anthropogenic

influences on the environment. Finally, ecosystem function and diversity can be

monitored with community samples, although this was not done in the present analysis.

The index of biotic integrity (Karr 1981; Simon 1999), for example, is derived from

community samples and can provide local information on the environment.

66

ACKNOWLEDGMENTS

Bill Pflieger initiated this project in 1992 and began the field work. Sue Bruenderman

finished most of the field work from 1994 to 1996. Many other MDC fisheries biologists

also contributed to the field work. Thanks to Tom Russell, Mike Roell, Bob Hrabik, and

Ron Dent for reviewing the manuscript and making many useful suggestions for

improvement.

LITERATURE CITED

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72

APPENDIX

Appendix Table 1. Species traits used in this analysis. Number of basins = number of 8-digit hydrological units in which a species was ever collected according to the MDC fish community database. Trophic type = trophic level or feeding group (FF=filter feeder, BI=benthic invertivore, O=omnivore, H=herbivore, GI=general invertivore, IP=invertivore/piscivore [Berkman and Rabeni 1987; Rabeni and Smale 1995; Pflieger 1997]). Spawning substrate = substrate on which species spawns or reproductive group (SL=simple-lithophilous, SM=simple miscellaneous, CPC=complex-parental care, CNPC=complex-no parental care [Berkman and Rabeni 1987; Rabeni and Smale 1995; Pflieger 1997]). Range edge = range edge in Missouri not defined by a drainage boundary (N, S, E, W, NW, NE, SW, SE [Lee et al. 1980; Pflieger 1997]). Region type = region for which species is most characteristic (lowland, Ozark, prairie, river [Pflieger 1989]). Stream type = characteristic stream type in its most characteristic region (prairie headwater, prairie creek, prairie small river, prairie large river, Ozark headwater, Ozark creek, Ozark small river, Ozark large river, lowland large natural, lowland small natural, lowland clear ditch, lowland muddy ditch, lowland standing, river lower Mississippi, river upper Mississippi, river Missouri [Pflieger 1989]). Number Trophic Spawning Range Region Stream of basins Family type substrate edge type type Alabama shad 6 Clupeidae GI SL N Ozark large river Arkansas darter 1 Percidae BI SL Ozark headwater Arkansas River orangethroat darter 25 Percidae BI SL Ozark headwater Arkansas saddled darter 2 Percidae BI SL Ozark large river Banded darter 9 Percidae BI SM Ozark small river Banded fantail darter 22 Percidae BI C-PC Ozark creek Banded pigmy sunfish 5 Elassomatidae GI SM NW lowland standing Banded sculpin 12 Cottidae BI C-PC Ozark small river Bantam sunfish 2 Centrarchidae GI C-PC N lowland standing Bigeye chub 7 Cyprinidae BI SL NW Ozark large river Bigeye shiner 18 Cyprinidae GI SL NW Ozark small river Bigmouth shiner 25 Cyprinidae O SL S plains creek Blacknose shiner 6 Cyprinidae BI SL S plains creek Blackside darter 14 Percidae BI SL plains small river Blackspotted topminnow 15 Fundulidae GI SM N Ozark creek Blackstripe topminnow 22 Fundulidae GI SM plains creek Blacktail shiner 9 Cyprinidae GI SM N lowland large natural Bleeding shiner 9 Cyprinidae GI C-NPC N Ozark small river Bluegill 34 Centrarchidae GI C-PC lowland standing Bluestripe darter 2 Percidae BI SL Ozark small river Bluntface shiner 1 Cyprinidae GI SM Ozark large river Bluntnose darter 15 Percidae BI SM NW lowland clear ditch Bluntnose minnow 30 Cyprinidae O C-PC Ozark large river Brassy minnow 4 Cyprinidae H SM S plains creek Brindled madtom 5 Ictaluridae BI C-PC NW Ozark small river Brook darter 1 Percidae BI SL Ozark headwater Brook silverside 25 Atherinidae GI SM Ozark large river Bullhead minnow 17 Cyprinidae O C-PC lowland large natural Cardinal shiner 1 Cyprinidae GI C-NPC Ozark small river Central mudminnow 2 Umbridae BI SM SW plains headwater Central stoneroller 31 Cyprinidae H SL Ozark headwater Checkered madtom 2 Ictaluridae BI C-PC Ozark small river Channel darter 1 Percidae BI SL NW plains small river Common shiner 9 Cyprinidae GI C-NPC S plains creek Creek chub 31 Cyprinidae IP C-NPC plains headwater Creek chubsucker 7 Catastomidae O SL NW Ozark headwater Crystal darter 5 Percidae BI SL W Ozark large river Current darter 1 Percidae BI SL Ozark headwater Current River saddled darter 2 Percidae BI SL Ozark large river Cypress darter 6 Percidae BI SM N lowland standing Cypress minnow 3 Cyprinidae H SM N lowland large natural Dollar sunfish 2 Centrarchidae GI C-PC N lowland small natural Dusky darter 6 Percidae BI SL NW lowland turbid ditch Duskystripe shiner 1 Cyprinidae GI C-NPC Ozark creek Eastern redfin shiner 25 Cyprinidae GI C-NPC Ozark creek Eastern slim minnow 5 Cyprinidae O C-PC NW Ozark large river Emerald shiner 33 Cyprinidae GI SM river lower MS Fathead minnow 32 Cyprinidae O C-PC plains headwater Flier 6 Centrarchidae GI C-PC NW lowland standing Freckled madtom 16 Ictaluridae BI C-PC NW lowland large natural

73

Appendix Table 1 (continued). Species traits used in this analysis. Number of basins = number of 8-digit hydrological units in which a species was ever collected according to the MDC fish community database. Trophic type = trophic level or feeding group (FF=filter feeder, BI=benthic invertivore, O=omnivore, H=herbivore, GI=general invertivore, IP=invertivore/piscivore [Berkman and Rabeni 1987; Rabeni and Smale 1995; Pflieger 1997]). Spawning substrate = substrate on which species spawns or reproductive group (SL=simple-lithophilous, SM=simple miscellaneous, CPC=complex-parental care, CNPC=complex-no parental care [Berkman and Rabeni 1987; Rabeni and Smale 1995; Pflieger 1997]). Range edge = range edge in Missouri not defined by a drainage boundary (N, S, E, W, NW, NE, SW, SE [Lee et al. 1980; Pflieger 1997]). Region type = region for which species is most characteristic (lowland, Ozark, prairie, river [Pflieger 1989]). Stream type = characteristic stream type in its most characteristic region (prairie headwater, prairie creek, prairie small river, prairie large river, Ozark headwater, Ozark creek, Ozark small river, Ozark large river, lowland large natural, lowland small natural, lowland clear ditch, lowland muddy ditch, lowland standing, river lower Mississippi, river upper Mississippi, river Missouri [Pflieger 1989]). Number Trophic Spawning Range Region Stream of basins Family type substrate edge type type Ghost shiner 19 Cyprinidae GI SM river lower MS Gilt darter 6 Percidae BI SL W Ozark large river Golden shiner 31 Cyprinidae O SM plains headwater Golden topminnow 1 Fundulidae GI SM N lowland clear ditch Goldstripe darter 2 Percidae BI SM N lowland small natural Gravel chub 10 Cyprinidae BI SL Ozark large river Greenside darter 12 Percidae BI SM NW Ozark small river Green sunfish 35 Centrarchidae GI C-PC plains headwater Harlequin darter 5 Percidae BI SM NW lowland large natural Hornyhead chub 15 Cyprinidae O C-NPC Ozark small river Ironcolor shiner 3 Cyprinidae GI SM W lowland clear ditch Johnny darter 26 Percidae BI C-PC plains creek Lake chubsucker 5 Catastomidae O SM NW lowland clear ditch Largescale stoneroller 15 Cyprinidae H SL Ozark small river Least darter 6 Percidae BI SM Ozark headwater Longear sunfish 19 Centrarchidae GI C-PC Ozark small river Longnose darter 2 Percidae BI SL Ozark large river Meramec River saddled darter 4 Percidae BI SL Ozark large river Mimic shiner 12 Cyprinidae GI SM lowland large natural Mississippi silvery minnow 17 Cyprinidae H SM W lowland large natural Missouri saddled darter 4 Percidae BI SL Ozark large river Mottled sculpin 6 Cottidae BI C-PC Ozark creek Mountain madtom 2 Ictaluridae BI C-PC NW Ozark large river Mud darter 10 Percidae BI SM W lowland clear ditch Neosho madtom 1 Ictaluridae BI C-PC NE Ozark large river Niangua darter 1 Percidae BI SL Ozark small river Northern logperch 26 Percidae BI SL river upper MS Northern orangethroat darter 25 Percidae BI SL Ozark headwater Northern studfish 15 Fundulidae GI SM N Ozark small river Ohio logperch 26 Percidae BI SL Ozark large river Orangespotted sunfish 33 Centrarchidae GI C-PC plains small river Ozark chub 3 Cyprinidae BI SL Ozark large river Ozark logperch 26 Percidae BI SL Ozark large river Ozark madtom 3 Ictaluridae BI C-PC Ozark small river Ozark minnow 13 Cyprinidae O C-NPC W Ozark creek Ozark sculpin 9 Cottidae BI C-PC Ozark creek Ozark shiner 3 Cyprinidae BI SL Ozark large river Pallid shiner 7 Cyprinidae BI SM W lowland large natural Peppered chub 13 Cyprinidae BI SM river lower MS Pirate perch 9 Aphredoderidae GI SM W lowland clear ditch Plains killifish 5 Fundulidae O SL E plains creek Plains minnow 16 Cyprinidae H SM E river Missouri Plains orangethroat darter 25 Percidae BI SL plains headwater Plains topminnow 7 Fundulidae GI SM E Ozark headwater Pugnose minnow 9 Cyprinidae GI C-PC NW lowland standing Rainbow darter 11 Percidae BI SL Ozark creek Redear sunfish 9 Centrarchidae GI C-PC N Ozark large river Redfin darter 1 Percidae BI SM N plains small river Red shiner 31 Cyprinidae GI SM plains large river Redspot chub 1 Cyprinidae O C-NPC Ozark small river Redspotted sunfish 7 Centrarchidae GI C-PC NW lowland clear ditch Ribbon shiner 6 Cyprinidae GI C-NPC NW lowland clear ditch River darter 11 Percidae BI SL river middle MS Rosyface shiner 14 Cyprinidae GI C-NPC Ozark large river

74

Appendix Table 1. Species traits used in this analysis. Number of basins = number of 8-digit hydrological units in which a species was ever collected according to the MDC fish community database. Trophic type = trophic level or feeding group (FF=filter feeder, BI=benthic invertivore, O=omnivore, H=herbivore, GI=general invertivore, IP=invertivore/piscivore [Berkman and Rabeni 1987; Rabeni and Smale 1995; Pflieger 1997]). Spawning substrate = substrate on which species spawns or reproductive group (SL=simple-lithophilous, SM=simple miscellaneous, CPC=complex-parental care, CNPC=complex-no parental care [Berkman and Rabeni 1987; Rabeni and Smale 1995; Pflieger 1997]). Range edge = range edge in Missouri not defined by a drainage boundary (N, S, E, W, NW, NE, SW, SE [Lee et al. 1980; Pflieger 1997]). Region type = region for which species is most characteristic (lowland, Ozark, prairie, river [Pflieger 1989]). Stream type = characteristic stream type in its most characteristic region (prairie headwater, prairie creek, prairie small river, prairie large river, Ozark headwater, Ozark creek, Ozark small river, Ozark large river, lowland large natural, lowland small natural, lowland clear ditch, lowland muddy ditch, lowland standing, river lower Mississippi, river upper Mississippi, river Missouri [Pflieger 1989]). Number Trophic Spawning Range Region Stream of basins Family type substrate edge type type Sabine shiner 1 Cyprinidae O SM N lowland large natural Saddleback darter 5 Percidae BI SL lowland turbid ditch Sand shiner 27 Cyprinidae O SL SE plains small river Scaly sand darter 4 Percidae BI SL N lowland large natural Silver chub 26 Cyprinidae BI SM river lower MS Silverjaw minnow 5 Cyprinidae BI SL W Ozark creek Slenderhead darter 19 Percidae BI SL plains large river Slender madtom 19 Ictaluridae BI C-PC Ozark creek Slough darter 10 Percidae BI SM NW lowland clear ditch Southern redbelly dace 17 Cyprinidae O C-NPC Ozark headwater Speckled darter 6 Percidae BI SL Ozark small river Spotfin shiner 9 Cyprinidae GI SM Ozark large river Spring cavefish 1 Amblyopsidae GI C-PC NW lowland standing Starhead topminnow 4 Fundulidae GI SM W lowland standing Steelcolor shiner 7 Cyprinidae GI SM NW Ozark large river Stargazing darter 1 Percidae BI SL NW Ozark large river Stippled darter 9 Percidae BI SL N Ozark headwater Stonecat 18 Ictaluridae BI C-PC S plains large river Striped fantail darter 22 Percidae BI C-PC Ozark creek Striped shiner 18 Cyprinidae GI C-NPC NW Ozark creek Suckermouth minnow 32 Cyprinidae BI SL plains small river Swamp darter 1 Percidae BI SM N lowland turbid ditch Tadpole madtom 22 Ictaluridae BI C-PC lowland clear ditch Taillight shiner 3 Cyprinidae O SM NW lowland turbid ditch Telescope shiner 4 Cyprinidae GI SL NW Ozark creek Topeka shiner 7 Cyprinidae BI C-NPC SE plains creek Trout-perch 10 Percopsidae BI SM S plains small river Warmouth 18 Centrarchidae GI C-PC lowland standing Wedgespot shiner 8 Cyprinidae BI SL N Ozark large river Weed shiner 5 Cyprinidae GI SM W lowland clear ditch Western mosquitofish 32 Poecilliidae GI C-PC N lowland standing Western redfin shiner 25 Cyprinidae GI C-NPC plains creek Western sand darter 6 Percidae BI SL river upper MS Western silvery minnow 14 Cyprinidae H SM SE river Missouri Western slim minnow 5 Cyprinidae O C-PC NE Ozark large river White River fantail darter 22 Percidae BI C-PC Ozark creek White River orangethroat darter 25 Percidae BI SL Ozark headwater Whitetail shiner 3 Cyprinidae GI SM NW Ozark large river Yoke darter 1 Percidae BI SL Ozark small river

75

Appendix Figure 1. Arkansas River orangethroat darter (Etheostoma spectabile

squamosum).

76

Appendix Figure 2. Banded darter (Etheostoma zonale).

77

Appendix Figure 3. Banded sculpin (Cottus carolinae).

78

Appendix Figure 4. Bigeye chub (Notropis amblops).

79

Appendix Figure 5. Bigeye shiner (Notropis boops).

80

Appendix Figure 6. Bigmouth shiner (Notropis dorsalis).

81

Appendix Figure 7. Blacknose shiner (Notropis heterolepis).

82

Appendix Figure 8. Blackside darter. (Percina maculata).

83

Appendix Figure 9. Blackspotted topminnow (Fundulus olivaceus).

84

Appendix Figure 10. Blackstripe topminnow (Fundulus notatus).

85

Appendix Figure 11. Blacktail shiner (Cyprinella venusta).

86

Appendix Figure 12. Bleeding shiner (Luxilus zonatus).

87

Appendix Figure 13. Bluegill (Lepomis macrochirus).

88

Appendix Figure 14. Bluestripe darter (Percina cymatotaenia).

89

Appendix Figure 15. Bluntface shiner (Cyprinella camura).

90

Appendix Figure 16. Bluntnose darter (Etheostoma chlorosomum).

91

Appendix Figure 17. Bluntnose minnow (Pimephales notatus).

92

Appendix Figure 18. Brook silverside (Labidesthes sicculus).

93

Appendix Figure 19. Bullhead minnow (Pimephales vigilax).

94

Appendix Figure 20. Cardinal shiner (Luxilus cardinalis).

95

Appendix Figure 21. Central stoneroller (Campostoma anomalum).

96

Appendix Figure 22. Common shiner (Luxilus cornutus).

97

Appendix Figure 23. Creek chub (Semotilus atromaculatus).

98

Appendix Figure 24. Creek chubsucker (Erimyzon oblongus).

99

Appendix Figure 25. Duskystripe shiner (Luxilus pilsbryi).

100

Appendix Figure 26. Eastern redfin shiner (Lythrurus umbratilis cyanocephalus).

101

Appendix Figure 27. Emerald shiner (Notropis atherinoides).

102

Appendix Figure 28. Fathead minnow (Pimephales promelas).

103

Appendix Figure 29. Freckled madtom (Noturus nocturnus).

104

Appendix Figure 30. Ghost shiner (Notropis buchanani).

105

Appendix Figure 31. Gilt darter (Percina evides).

106

Appendix Figure 32. Golden shiner (Notemigonus crysoleucas).

107

Appendix Figure 33. Gravel chub (Erimystax x-punctatus).

108

Appendix Figure 34. Greenside darter (Etheostoma blennioides).

109

Appendix Figure 35. Green sunfish (Lepomis cyanellus).

110

Appendix Figure 36. Hornyhead chub (Nocomis biguttatus).

111

Appendix Figure 37. Johnny darter (Etheostoma nigrum).

112

Appendix Figure 38. Largescale stoneroller (Campostoma oligocephalus).

113

Appendix Figure 39. Longear sunfish (Lepomis megalotis).

114

Appendix Figure 40. Meramec River saddled darter (Etheostoma tetrazonum).

115

Appendix Figure 41. Mimic shiner (Notropis volucellus).

116

Appendix Figure 42. Mississippi silvery minnow (Hybognathus nuchalis).

117

Appendix Figure 43. Missouri saddled darter (Etheostoma tetrazonum).

118

Appendix Figure 44. Mottled sculpin/Ozark sculpin (Cottus bairdi/Cottus hypselurus).

119

Appendix Figure 45. Northern logperch (Percina caprodes semifasciata).

120

Appendix Figure 46. Northern orangethroat darter (Etheostoma spectabile spectabile).

121

Appendix Figure 47. Northern studfish (Fundulus catenatus).

122

Appendix Figure 48. Ohio logperch (Percina caprodes caprodes).

123

Appendix Figure 49. Orangespotted sunfish (Lepomis humilis).

124

Appendix Figure 50. Ozark chub (Erimystax harryi).

125

Appendix Figure 51. Ozark logperch (Percina caprodes fulvitaenia).

126

Appendix Figure 52. Ozark madtom (Noturus albater).

127

Appendix Figure 53. Ozark minnow (Notropis nubilus).

128

Appendix Figure 54. Ozark shiner (Notropis ozarcanus).

129

Appendix Figure 55. Pallid shiner (Notropis amnis).

130

Appendix Figure 56. Peppered chub (Macrhybopsis tetranema).

131

Appendix Figure 57. Plains minnow (Hybognathus placitus).

132

Appendix Figure 58. Plains topminnow (Fundulus sciadicus).

133

Appendix Figure 59. Pugnose minnow (Opsopoeodus emiliae).

134

Appendix Figure 60. Rainbow darter (Etheostoma caeruleum).

135

Appendix Figure 61. Red shiner (Cyprinella lutrensis).

136

Appendix Figure 62. Redspot chub (Nocomis asper).

137

Appendix Figure 63. Redspotted sunfish (Lepomis miniatus).

138

Appendix Figure 64. Ribbon shiner (Lythrurus fumeus).

139

Appendix Figure 65. Rosyface shiner (Notropis rubellus).

140

Appendix Figure 66. Sand shiner (Notropis ludibundus).

141

Appendix Figure 67. Silver chub (Macrhybopsis storeriana).

142

Appendix Figure 68. Slenderhead darter (Percina phoxocephala).

143

Appendix Figure 69. Slender madtom (Noturus exilis).

144

Appendix Figure 70. Slough darter (Etheostoma proeliare).

145

Appendix Figure 71. Southern redbelly dace (Phoxinus erythrogaster).

146

Appendix Figure 72. Speckled darter (Etheostoma stigmaeum).

147

Appendix Figure 73. Spotfin shiner (Cyprinella spiloptera).

148

Appendix Figure 74. Steelcolor shiner (Cyprinella whipplei).

149

Appendix Figure 75. Stippled darter (Etheostoma punctulatum).

150

Appendix Figure 76. Stonecat (Noturus flavus).

151

Appendix Figure 77. Striped fantail darter (Etheostoma flabellare lineolatum).

152

Appendix Figure 78. Striped shiner (Luxilus chrysocephalus).

153

Appendix Figure 79. Suckermouth minnow (Phenacobius mirabilis).

154

Appendix Figure 80. Tadpole madtom (Noturus gyrinus).

155

Appendix Figure 81. Telescope shiner (Notropis telescopus).

156

Appendix Figure 82. Topeka shiner (Notropis topeka).

157

Appendix Figure 83. Trout-perch (Percopsis omiscomaycus).

158

Appendix Figure 84. Warmouth (Lepomis gulosus).

159

Appendix Figure 85. Wedgespot shiner (Notropis greenei).

160

Appendix Figure 86. Weed shiner (Notropis texanus).

161

Appendix Figure 87. Western mosquitofish (Gambusia affinis).

162

Appendix Figure 88. Western redfin shiner (Lythrurus umbratilis umbratilis).

163

Appendix Figure 89. White River orangethroat darter (Etheostoma spectabile).

164

Appendix Figure 90. Whitetail shiner (Cyprinella galactura).

165

Appendix Figure 91. Yoke darter (Etheostoma juliae).