January 1998

22nd Annual Larval Fish ConferenceJuly 9 - July 13, 1998 — Ann Arbor, MI

See page 10 for meeting details.

Jan 1998Volume 18, Number 3

Newsletter of the AFS EarlyLife History Section

PRESIDENT’S MESSAGEInside this Issue

m President’s messagem News from the re-

gionsm Northeastm Southernm Internationalm Meeting reviewsm 21st Larval Fish

Conferencem 1st FONE Confer-

encem Upcoming meetings

Abstract Deadlines:

ASIH: March 13to be held July 13-16,1998 on the campus ofthe University of Guelph,Guelph, Ont

22ndLarval Fish Conference - May 1to be held July 9-13 onthe campus of the Univer-sity of Michigan. seePage 10.

The 22nd Annual Larval Fish Conference (LFC) will be heldthis year on 9-13 July in Ann Arbor, MI, under the stewardship oflocal host Ed Rutherford. I am especially looking forward to theconference this year, as it is the first year in several that the LFC willnot meet in conjunction with ASIH's annual gathering. I enjoy thefocus on tiny fishes that meeting separately allows, and this year’sprogram will not disappoint. Nevertheless, I want to take thisopportunity to personally thank ASIH for allowing us to share thestage, and to encourage joint meetings in the future, perhaps everycouple of years or so.

There are two important items of section business that wemust address in the coming months. The first is the election of newofficers. Nominations for President-Elect, Secretary-Elect and Re-gional Representatives should be sent to Jim Cowan, c/o DauphinIsland Sea Lab, P.O. Box 369-370, Dauphin Island, AL 36528 or bye-mail to jcowan@jaguar1.usouthal.edu. Nominations will be ac-cepted through 15 April, 1998. Remember that nominees must bemembers of the ELHS and the AFS, and that officers can bere-elected. In addition, past officers can be nominated to serve againin any office, including the one that he/she formerly held.

The second concerns section governance. A sub-committee ofthe Section's EXCOM met at the Dauphin Island Sea Lab on February20-22 to prepare a draft of the Standing Rules to be considered forapproval by ELHS members at the business meeting in Ann Arbor.Standing Rules supplement the section's by-laws and formerly estab-lish duties of officers and committee responsibilities. After commentfrom the full EXCOM, an approval draft of the Standing Rules will bemade available to section members in advance of the business meeting,

2

NEWS FROM THE REGIONS

Masthead

President:Jim CowanDept. of Marine ScienceUniversity of South AlabamaMobile, AL 23388(205) 861-7535jcowan@jaguar1.usouthal.edu

President-Elect:John GovoniNOAA/NMFSSE Fisheries Science CenterBeaufort, NC 28516(919) 728-3595jgovoni@hatteras.bea.nmfs.gov

Secretary:David BengtsonDepartment of Zoology, URIKingston, RI 02881(401) 792-2372bengtson@uriacc.uri.edu

Secretary-Elect:Dave SecorCBL / UMCESSolomons, MD 20688(410) 326-7229secor@cbl.umces.edu

Treasurer:Kathy LangNOAA/NMFS166 Water StreetWoods Hole, MA 02543(508) 495-2237kathy.lang@noaa.gov

Editor:Tom MillerCBL / UMCESSolomons, MD 20688(410) 326-7276miller@cbl.cees.edu

Northeast Region - Ben Letcher, Popula-tion Ecology Section Leader, NationalBiological Service, S. O. Conte Anadro-mous Fish Research Center, One Mi-

gratory Way, P. O. Box 796, Turner Falls, MA01376. (Phone: (413) 863-8995 ext. 34, E-mail:bletcher@external.umass.edu).

New Brunswick Coop Fish and Wildlife Research Unit-University of New Brunswick.

Early life history studies: Winter habitat and survival of YOYsmallmouth bass in New Brunswick

The smallmouth bass in New Brunswick is at the northernextent of the species range. Harsh winter conditions of this northtemperate region limit the survival of young-of-the-year (YOY)through their first winter and therefore may govern regional popula-tion strength and viability.

Smallmouth bass typically over winter in a semi-torpid"hibernating" state, relying heavily on stored energy reserves tomaintain minimal metabolic activity. Theory in part suggests that forYOY these energy reserves are in short supply (in relation to theirhigher rate specific metabolism), and consequently, starvation mayexplain the substantial winter mortality evident in seasonal collectionsurveys.

As part of our studies of NB smallmouth bass, we areevaluating the importance of YOY body condition and wintering

(Continued on page 4)

perhaps in the next issue of Stage's, or as part of the LFC registrationmaterials in Ann Arbor.

Finally, I want to take a minute to personally congratulate EdHoude for his receipt of the Beverton Medal, given this past summerby the Fisheries Society of the British Isles, for outstanding contribu-tions to studies of larval fish ecology and fisheries science. Ed's workhas inspired and challenged us all, and has provided more thaninspiration to those whom have been lucky enough to work closelywith him. Fortunately, I count myself among the latter group; thus,while I admittedly am not without bias, I cannot think of a moredeserving Beverton Medalist.

Jim Cowan

January 1998

Welcome to the

EARLY LIFE HISTORY SEC-TION (ELHS)

Of the American Fisheries Society

Welcome to our new home page! The purpose of these pages isto provide a rapid means to disseminate information to ELHSmembers and anyone looking for information about the ELHSsection. As such, these pages will complement Stages , our offi-cial newsletter

We are currently testing an online version of Stages . Follow theELHS Newsletter link in the Directory on the left of the screen

Although still under construction, we hope you will find thesepages informative in their present form. If you encounter anyproblem in viewing this page, please let me know (include thesize and resolution of the monitor in your message).

Some of the items currently under consideration for inclusion inthese pages are a searchable (and updateable) membership list,downloadable (pdf) versions of older issues of Stages, and anarchive of larval fish images and drawings. If you have anycomments on these or other elements of these pages, or if youhave an ELHS web-page you would like to see linked under the“Other Links” section, please email me.

John Dower ELHS Webmaster

Location http://www.eos.ubc.ca/afs_early

DIRECTORY

ELHS Home

About ELHS

ELHS Newsletter

Meetings

How to Join

Membership List

AFS Homepage

Other Links

Visit to new ELHS Homepage!!The site contains full details of meetings, amembership directory and back issues of

Stages!!!

4

habitat in their quest for winter survival. To do so,seasonal habitat requirements are surveyed by directunderwater observation and trapping, and naturalfield experiments are used to test YOY winter sur-vival among variable winter habitat treatments.

The effects of land use on early life history stagesof brook trout (Salvelinus fontinalis) on PrinceEdward Island.

W. Scott MacNeill and R. Allen Curry.have been investigating the early life history ofbrook trout on Prince Edward Island (PEI). PEI’srecreational fisheries resources have been signifi-cantly degraded by the construction of dams, pollu-tion from agricultural runoff, and soil erosion fromland cultivation. Erosion is considered the mostserious environmental problem facing PEI streams.We are examining the effects of land use practiceson the early life history stages of brook trout(Salvelinus fontinalis). We observed a lower den-sity of juveniles in watersheds with a greater propor-tion of land in agriculture (80% vs. 60%). Survivalto emergence increased as the proportion of agricul-tural land decreased (0-20% vs. 50-65%), except inareas of high ground water discharge.

The large agricultural industry on PrinceEdward Island (PEI) has created serious problemsfor the conservation of its natural resources. Fresh-water fisheries resources dependent on the mainte-nance of natural conditions have been significantlydegraded by the construction of dams, pollutionfrom agricultural runoff , and soil erosion from landcultivation

This study examines the impacts of sedi-ment on brook trout reproductive success, the mech-anisms of the impacts, and potential interim reme-dial actions to mitigate the effects of excess streamsedimentation.

All field experiments were conducted ontwo Prince Edward Island watersheds (the West andthe Wilmot Rivers). The Wilmot River is located inan area with intensive agriculture (heavy siltation)and the West River has a more forested drainagebasin (little siltation). Potential spawning sites wereidentified by the presence of suitable spawninggravel, groundwater seepages, and newly emerged

fry.Trout redds were located and mapped by

foot surveys, and identified for: 1) groundwaterdischarge and chemistry; 2) temporal changes insubstrate composition during incubation; 3) sur-vival from egg to alevin emergence from the gravel.

It is anticipated that we will determine theoverall impacts of sediment on brook trout popula-tions in PEI streams and the relative importance ofspawning habitat sedimentation and juvenile rearinghabitat sedimentation in limiting brook trout popula-tions. In addition, we will determine the extent towhich spawning in spring-influenced areas reducesthe impact of sedimentation on brook trout repro-ductive success, or whether insufficient availabilityof such areas force brook trout to spawn in poorareas where reproductive success is lower.

For more information on any of the workdescribed above, please contact:

Scott MacNeill or Allen CurryNew Brunswick Cooperative Fish and Wildlife Re-

search Unit, Biology Department,

University of New Brunswick,Fredericton, NB. E3B 6E1.

Canada(506) 453-4584

Email:racurry@unb.ca

Biological Sciences, Rutgers University

Judith Weis's lab at Rutgers has been study-ing effects of embryonic and larval exposures totoxicants on larval behavior. Tong Zhou finishedher Ph.D. thesis last June examining the develop-ment of feeding and anti-predator behavior in mum-michogs and looking at the effects of methylmercuryexposures during embryonic and/or larval stages onthe behavior. She also compared effects on popula-tions from clean vs. polluted environments. Somepopulation differences can be attributed to the envi-ronmental history of the fish, but other differencesmay be inherent. She has also anlayzed the neuro-transmitters in control vs. treated larvae and founddifferences which may be associated with the behav-ioral effects. Papers are in press in "Aquatic Toxi-cology" and others are in the process of being

(Continued from page 2)

January 1998

submitted and/or revised.Jennifer Samson has been looking at behav-

ior in zebra danio larvae after embryonic exposuresto methylmercury. It is clear that successful hatchafter low-dose exposure does not mean that every-thing is all right. The feeding and/or predator avoid-ance behavior of larvae may be severely compro-mised even though they hatched out at the appropri-ate time and look totally normal.

For more information, please contact:Judith Weis,

Department of Biological SciencesRutgers UniversityRutgers, NJ 07102

(973) 353-5387Email: jweis@andomeda.rutgers.edu

University of Rhode Island, GraduateSchool of Oceanography

Grace Klein-MacPhee and Barbara Sulli-van are conducting experiments on predation ratesof the planktonic hydroid, Clytia gracilis on cod andhaddock in the MERL mesocosms. This hydroidhas been found in large numbers on Georges Bankoverlapping spatially and temporally with cod andhaddock larvae. Preliminary small scale experimentsshowed that hydroids were capable of capturing andingesting cod larvae and had the potential to beimportant predators and/or competitors of cod andhaddock on Georges Bank. Grace and Barbara arecontinuing large scale mesocosm experiments on theeffects of turbulence on predation rates of the hy-droids on cod larvae. This is part of the predationcomponent of the Georges Bank GLOBEC studieswhich are designed in part to address the question ofhow global climate change might effect the distribu-tion abundance and production of animals in the sea.Zooplankton and ichthyoplankton are the focus be-cause they form links between the phytoplanktonand higher trophic levels. Research efforts are fo-cused on the dynamics of zooplankton and larvalfish populations on Georges Bank in order to yieldnew insights into the coupling between physical andbiological rocesses.

The group presented papers at the 1997ICES Annual Science Conference in BaltimoreMaryland September 25-October 3 (See Sept 1997

Stages for Meeting Review). The paper presentedby Grace Klein-MacPhee was entitled "Mortality oflarval cod related to predation by the hydroid, Clytiagracilis, on Georges Bank" . Co-authors were B.K.Sullivan, D. Van Keuran, E. Horgan and E. Klos.A companion paper focusing on field data of hy-droids, cod and haddock was presented by BarbaraSullivan. The paper was entitled "Abundance anddistribution of planktonic hydroids with respect tolarval fish and hydrographic features on GeorgesBank". Co-authors were J. Williams, D. Van Keu-ran, R.G. Lough and J. Manning.

Grace Klein-MacPhee is conducting re-search on the tautog, Tautoga onitus, as a newspecies for aquaculture. She has been looking atlarval survival and growth on different artificialdiets, the effects of different anesthetics on larvaeand production of eggs by a captive broodstock. Anundergraduate Coastal Fellow, Richard Lovett, as-sisted in the research and focused on the anesthesiastudies and larval growth and survival. A summervolunteer student Brian Walker from RogerWilliams University also assisted in larval diet eval-uation. The research is supported by a Rhode IslandOcean Technology Center Grant.

Grace has also been working on the effectsof temperature and salinity, and the effects of timingand frequency of feeding on growth of summerflounder juveniles. This is part of a summer flounderaquaculture project sponsored by Rhode Island SeaGrant. Grace has been assisted by Riley Young andBrian Murphy, graduate students at URI Fish Vet-erinary and Animal Science Department.

For more information on any of these pro-jects please contact:

Grace Klein MacPheeGSO, University of Rhode Island

Narragansett, RI(401) 792-6695

gracemac@gsosum1.gso.uri.edu

6

Maurice Lamontagne Institute, Departmentof Fisheries and Oceans Canada, Mont-Joli,Quebec, Canada.

This report summarizes some of the larvalfish research being conducted at IML, by threeresearch groups.

From the laboratory of Patrick Ouellet

Patrick has been conducting an extensiveresearch program on maternal influences on eggquality in Atlantic cod, lobster and crab as a part ofa larger collaborative project. The research pro-gramme is aimed at providing information on thecauses of the recent collapse of the northern Gulf ofSt. Lawrence cod stock. Along with the decline inabundance, fisheries data revealed that the charac-teristics of the fish were changing, e.g. smaller andlower condition of the spawning cod. Moreover,from 1993 to 1995 a series of cruises in early springover one cod spawning ground in the northeast Gulfreveal that cod eggs were more abundant below thesurface within the cold (0°C) water layer. Thisobservation suggested a low buoyancy problem forthese eggs since such low water temperature isdetrimental to successful development. In order tounderstand how smaller size and/or the lower nutri-tional condition of female cod can be responsible forlower egg quality, Patrick began a series of experi-ents on cod egg characteristics and viability relativeto female size and condition, in collaboration withcolleagues at IML. In 1995 and 1996, cod of differ-ent size classes were conditioned at two (low vs.high) feeding regimes and two temperatures (~2°C -~6°C) to produce a range of maternal condition (seeDutil et al. 1998). Over the two spawning seasons,subsamples of eggs from every egg batch spawnedfrom 44 females (a set of 22 different females eachyear) were analyzed for egg size, dry mass, energycontent and, in some case, density measurements(i.e. specific gravity). In addition, a total of 54 eggbatches from 24 individual females (about 2 eggbatches/female each year) were used to monitordevelopment rate and survival from day one tohatching at two temperatures (~0°C - ~4°C). Theexperiments produced a large data set on whichanalysis is as yet incomplete. Nevertheless, a mas-

ters thesis was produced in 1997 and two primarypublications are in preparation for 1998 (see bibli-ography below).

Briefly, the results to date indicate thatfemale size and condition combined influence meanegg characteristics (size, dry mass) and hatchingsuccess was weakly related to female condition;hatching was better in egg batches from females inhigher pre-spawning condition (Ouellet et al. inprep.).

Another aspect of the project on cod eggsdeals with the effect of temperature on egg yolkosmolality, and hence buoyancy. A partial loss ofosmotic control at low temperature was advanced asone possible cause of the low buoyancy in cod eggsobserved in the northeast Gulf. The hypothesis wastested by measuring yolk osmolality of cod eggsincubated at the same and constant salinity and attwo temperatures (0°C - 4°C). The experimentshowed that cod eggs incubated at low temperatureacquired higher osmolality and the differences be-tween treatments increased with time, i.e. develop-mental stage (Bérubé et al. in prep.). Moreover, eggdiameter appears to be an important factor for thecontrol of egg osmolality. In parallel experiments,larger eggs showed less changes in yolk osmolalitywhen transferred to different salinity (Bérubé et al.,in prep.). Since egg size is a variable, at least inpart, determined by maternal phenotype, the resultssuggest that such maternal effects must be consid-ered when considering the overall influence of envi-ronmental factors on fish eggs and larvae dynamics.

The work on cod eggs is part of a broaderprogram on maternal effects. Maternal effects onsnow crab and lobster egg and larval characteristicsare now being investigated. The rationale for thisapproach is that exploitation alters greatly the de-mographic structure of a population, not only thenumbers of adults (spawners) is reduced but also itis possible to observe changes in size at maturity,condition, etc. Those conditions must affect eggproduction in populations both quantitatively andqualitatively. Environmental influences on early lifehistory stages can be compared to a screening pro-cess where only the luckiest or more fit survive. Theresearch effort presented here can contribute tore-introduce the spawning stock into the recruitmentequation. Spawning is when heterogeneity is created

January 1998

in egg/larval populations. Understanding that mo-ment of the life cycle can only improve our under-standing of how environmental factors ultimatelydetermine the number of survivors.

For more information on any aspect of thiswork, please contact Patrick directly, at

Dr. Patrick OuelletInstitute Maurice LaMontagne

IDFO850 Route de la Mer

Mont-Joli, QCG5H 3Z4

(418) 775-0500p_ouellet@iml3.iml.dfo.ca

or see any of the following publications that haveresulted from this work:Bérubé, I., Ouellet, P. and Brêthes, J.-C. (in prep.). Effects ofegg size and water temperature on yolk osmolality in cod eggs(Gadus morhua L.).

Bérubé, I. 1998. Effet de la taille et de la condition desfemelles de morue franche (Gadus morhua) sur la qualité desoeufs et sur leur capacité de maintenir leur équilibre osmo-tique. Mémoire de maîtrise. Université du Québec à Ri-mouski. 90 pp.

Dutil, J.-D., M. Castonguay, M.O. Hammill, P. Ouellet, Y.Lambert, D. Chabot, H. Browman, D. Gilbert, A. Fréchet.J.-A. Gagné, D. Gascon & L. Savard. 1998. Environmentalinfluences on the productivity of cod stocks: some evidence

for the northern Gulf of St. Lawrence, and required changes inmanagement practices. Department of Fisheries and Oceans(Canada). Atlantic Fisheries Research Document 98/18: 42p.

Ouellet, P., Lambert, Y., and Castonguay, M. 1997. Spawningof Atlantic cod (Gadus morhua) in the northern Gulf of St.Lawrence: a study of adult and egg distribution and character-istics. Can. J. Fish. Aquat. Sci., 54: 198-210.

Ouellet, P. 1997. Characteristics and vertical distribution ofAtlantic cod (Gadus morhua) eggs in the northern Gulf of St.Lawrence, and the possible effect of cold water temperature inrecruitment. Can. J. Fish. Aquat. Sci., 54: 211-223.

Ouellet, P., Lambert, Y., and Bérubé, I. (in prep.). Cod eggcharacteristics and viability related to maternal size andnutritional condition.

From the laboratory of Jean-Denis Dutil andYvan Lambert

Jean-Denis and Yvan have been studyingthermal tolerance of redfish larvae. Recruitment hasbeen poor in redfish stocks for a long period.Though this may have resulted from high rates offishing mortality among heavily exploited adult seg-ments of the population, unfavorable environmentalconditions may also have contributed to a lowersurvival rate of larvae and juveniles. Larval redfishin the Gulf of St. Lawrence are released below thecold intermediate water layer (CIL) and presumablyhave to make their way through near 0°C waters inorder to reach surface waters where feeding andgrowth take place. CIL waters have been colder than

Located outside of Rimouski, Quebec, The Maurice Lamontagne Institute is the Regional Science Directorate ofFisheries and Oceans - Canada, Laurentian Region. Research is conducted at IML on Fish and Marine Mam-mals, Invertebrates and Experimental Biology, Habitat Management and Environmental Sciences,and Ocean Sciences. The institute was inaguarated in 1987.

8

normal since the 1980's and this may have had animpact on larvae of Sebastes mentella and Sebastesfasciatus moving up the water column. These twospecies may also differ in their thermal require-ments.

Laboratory experiments have been con-ducted to assess the thermal tolerance of redfishlarvae. Gravid females were collected in May 1996and May 1997 and tolerance tests conducted onlarvae extruded from the ovaries. The 96-h testswere conducted at several temperatures, rangingfrom 0 to 18°C, both on freshly released larvae andon larvae deprived of food during 4 days. Lethaltemperatures will be compared to the range of tem-peratures encountered by the larvae in the field.Samples were also collected in the laboratory toassess the effect of temperature on the rate of lipidand protein utilization. Field samples collected in theperiod between late-April and late-June will allowan estimate of the maternal and hatching time effectson the size of larvae and on the level of lipid andprotein stores.

For more information, please contact:Dr. Jean-Denis Dutil

Institut Maurice-LamontagneDFO

850 Route de la MerMont-Joli, QC

G5H 3Z4(418) 775-0500

j_dutil@iml3.iml.dfo.ca

From the laboratory of Howard Browman

Howard has been conducted research intothree general areas that will be of interest to readersof Stages.

1.) The influence of maternal condition and ther-mal history on larval performance in Atlantic cod

The number of individuals that survivethrough the larval period is a major determinant ofrecruitment in many marine fish populations. Cur-rent hypotheses on the underlying mechanisms ofvariability in survival and recruitment in fish popu-lations concentrate on the importance of differentialgrowth and survival of individual larvae [e.g. the"Stage Duration" and the "Bigger is Better" hy-

potheses]. Maternal environmental and nutritionalhistories are likely related to the viability of individ-ual larvae, yet fisheries scientists have only recentlybegun to examine these relationships in detail. TheMaurice Lamontagne Institute’s multidisciplinaryresearch program on cod represents an attempt toevaluate these relationships.

Cod females are highly fecund, determinatespawners that release their eggs in batches. Therelationships between female condition and the num-ber and quality of eggs that they produce have onlyrecently been characterized for cod. For females ingood condition, these studies indicate that (1) 17-19egg batches are spawned per female over a period offour to six weeks, (2) the number of eggs liberatedin each batch varies significantly and generallyfollows a smooth dome-shaped curve, (3) egg sizeand dry mass decrease from the first to the lastbatch, (4) egg diameter of the first batch is posi-tively correlated with female length and (5) there isan inverse relationship between egg diameter andmortality. Further, cod females with high conditionfactors produce more previtellogenic oocytes anduse a larger fraction of them during vitellogenesisthan females with low condition factors. Overallfecundity is also related to female condition; femaleswith low condition factors produce fewer eggs thanthose with high condition factors.

Inter-batch and inter-female differences inegg quality may be translated to the larvae that theyproduce. Preliminary evidence indicates that thefeeding performance (numbers of prey ingested) ofcod larvae hatching from small eggs is poorer thanthat for larvae hatching from larger eggs. Similarresults have recently been reported for other species.Further, eggs liberated towards the end of a givenfemale's spawning cycle (i.e. those from the last fewegg batches) appear to produce larvae whose overallactivity is less than that for larvae from earlier eggbatches. Because activity and feeding rates translateinto rates of growth and survivorship, these obser-vations imply that cod larvae hatching from differ-ent egg batches, and/or from different females, maybe more-or-less viable.

Spawning in batches over a relatively long4-6 week period is thought to increase the chancesthat the larvae of any given female will encounterfeeding conditions adequate to support rapid growth

January 1998

and an increased chance of survival. However, thepreliminary results outlined above indicate that, forexample, larvae produced from eggs released late ina female's spawning cycle will be less likely to takeadvantage of good feeding conditions than larvaereleased during the middle of the same female'sspawning cycle.

Following from the above, the major thrustof this project was to test the following null hypothe-ses.(1) Female nutritional and thermal histories are notrelated to the performance of early larvae that they produce ;

(2) Female spawning and nutritional history are notrelated to the performance of early larvae.

Experiments were conducted during 1995-1996. Fertilized eggs were obtained from spawningcouples that had been maintained under differentfeeding and thermal regimes (see Dutil et al. 1998).Egg batches were transferred to an incubation sys-tem within a few hours of their release. At hatching,larvae were transferred to 60 litre black rearingbasins. The rearing basins were stocked with algae(Nanochloropsis sp.) and larvae were fed nutrition-ally enriched (Artemia Systems' Super Selco) ro-tifers (Brachionus sp.). Eggs and larvae were han-dled so as to maintain those from any givenmale-female cross and spawning batch event inisolation. Temperature was held at 6 °C and pho-toperiod was 14 h L : 10 h D.

We attempted to fill a 2 X 2 X 2, threereplicate experimental design, for a maximum of 24larval groups. In 1995, the treatments were: mater-nal ration (condition) X maternal thermal history Xegg batch number. In 1996, the treatments were:maternal ration (condition) X maternal size X eggbatch number. Three of the five or six male-femalepairs from each of the four ration-temperature treat-ment groups (in 1995), or ration-size treatmentgroups (in 1996) were targeted as sources of fertil-ized eggs. Measurements of egg quality on thesesame groups were also carried out (see Ouellet’sreport above, and Dutil et al. 1998). Two eggbatches from each of these females were targeted,the second or third (typically of relatively poorquality) and the fifth or sixth (typically of relativelyhigh quality) of any given female's spawning. All ofthe experiments were conducted at 6 °C.

Larvae from all targeted groups were sub-sampled at various intervals. Larval size was deter-mined from measurements on live larvae under amicroscope. Immediately after the standard lengthmeasurements, specimens were dried at 50°C for 24hours and then weighed on an electrobalance to thenearest 0.001 mg. Drying was continued until therewas no further change in mass. For each egg batch,10 to 12 larvae were collected from the rearingbasins at approximately 6 days post-hatch (DPH).At least three such measurements were obtainedprior to 20 DPH. Mean length and dry mass wereused to calculate the specific growth rate for mass(SGRm) and for standard length (SGRl).

The overall activity levels (percent timeactively swimming) and swimming patterns(swimming speed, frequency and duration of stops,repositioning turn angles) of the larvae were evalu-ated, at 3 & 6 DPH, using silhouette video photogra-phy (SVP). An SVP recording platform, along witha computer-controlled motion analysis system, wereused to obtain these data. These observations wereconducted on free-swimming cod larvae in a20×20×20 cm aquarium. Path analysis was used toevaluate whether there were any discernable differ-ences in activity levels or swimming patterns amongthe treatment groups. Fifty larvae were used in eachtrial, and there were three replicates per trial. Alldata were evaluated by two way ANOVA. At thiswriting, only the observations obtained during the1995 field season have been analyzed. We expect tocomplete the 1996 analysis by late summer 1998.

The range of pre-spawning condition factors(Fulton’s K, based upon total mass) in the femalesfor which larval groups were followed varied be-tween 0.88 and 1.25. There was no significantrelationship between the SGR (based upon either drymass or total length) of larvae and female conditionfactor or thermal history. Nor was there any signifi-cant relationship between larval activity or larvalswimming speed and female pre-spawning conditionfactor, at 3 or 6 DPH or thermal history. There wasa mildly significant (p = 0.038) treatment interactioneffect (female ration with temperature) on larvalSGR.

The results for 1995 indicate only a weakeffect of female condition factor and thermal history

(Continued on page 12)

10

Call for Abstracts

22nd Annual Larval Fish ConferenceUniversity of Michigan

Ann Arbor, MIJuly 9 - 13

For full details of the meeting please visit the meeting web site at

www.snre.umich.eduThe organisers encourage talks on all aspects of larval biologt, but are particularly interested in talksthat emphasize processes affecting survival or potential recruitment in both marine and freshwaterecosystems. In conference will feature sessions on otolith chemistry (see opposite), modeling studiesin early life history (Jim Cowan <Jcowan@jaguar1.usouthal.edu>), zooplankton / larval fish interac-tions (Dave Wahl <d-wahl@ux1.cso.uiuc.edu>, Tom Miller <miller@cbl.umces.edu> and RandyClaramunt <Randy_Claramunt @nbs.gov>) and early life history of fishes of the Great Lakes (DaveJude <djude@umich.edu>). If you are interested in being a part of one of these session, please contactthe session chairs. Contributed sessions will also be held.

The format for submitting abstracts will be outlined on the Web page. The page is designed so thatone may register and submit abstracts via the web page.

All abstracts are due by May 1.

The registration fee for the meeting has not yet been established, but will be announced on the web.

The organising committee has reserved up to 200 beds in the university dorms. The prices range from$34.50/night for singles, and $44/night for doubles. The number and person to call for reservationswill be listed on the web page. Attendees also can book reservations at local hotels. Some which arewithin walking distance include the Campus Inn (20 available rooms), the Michigan League (wherethe talks will be), the University Tower. Phone numbers for these places, and a general 800 number tocontact other hotels in the area. will also be provided These other places will be much more expen-sive.

No provisions have been made for meals. There are a number of restaurants within a short walk ofthe dorms and the meeting location, with a cafeteria and 2 fast food joints based in the same buildingas the meeting.

For students traveling to the meeting, travel grants are available from ELHS- see page 12.

January 1998

Otolith Chemistry Symposium, July 9-13, 1998

The 22nd Annual Larval Fish Conference will include a symposium on Otolith Chemistry.Presentations will include:

E. Beary1, K. Murphy1, S. Thorrold2 and S. Shuttleworth3, 1NIST, 2 Old Dominion Univer-sity and 3Washington University of St. Louis. Analysis of trace elements in otolith and water samplesusing ion chelation chromatography and isotope dilution ICPMS.

S. Campana, Department of Fisheries and Oceans, Canada. Otolith elemental fingerprints as bio-logical tracers of fish stocks.

G. Forrester1, S. Swearer2, M. Steele1, A. Brooks2 and D. Lea2, 1UCLA and 2UCSB.Trace-elemental fingerprinting using ICP-MS: are differences among sites in otolith chemistry consistentover time and among species?

B. Gillanders and M. Kingsford, University of Sydney. Determining linkages between estuarinenursery areas and coastal adult populations using isotopes in otoliths.

B. Kennedy1, R. Harrington2, C. Folt1, J. Blum1, and P. Chamberlain1, 1Dartmouth Collegeand 2University of Wyoming. Tracing the tributary origins and movements of anadromous Atlanticsalmon (Salmo salar) through the use of stable isotopes.

K. Limburg, University of Stockholm. Testing life history theory with otolith elemental ratios:juvenile American shad migration in the Hudson River Estuary, New York.

W. P. Patterson, Syracuse University. Early life history of Laurentian Great Lake Fishes from stableisotope ratios of carbon and oxygen: advances in computer-assisted micromilling.

W. F. Patterson III1, J. Cowan, Jr.1, B. Lyons2, and E. Graham2, 1University of SouthAlabama and 2University of Alabama. Otolith microchemistry fingerprints of age-0 red snapper,Lutjanus campechanus, in the northern Gulf of Mexico.

S. Swearer1, J. Harlan2, J. Caselle1, D. Lea1, & R. Warner1, 1UCSB and 2NOAA/University ofColorado. Island wakes and environmental markers: Using otolith elemental fingerprinting in studies oflarval dispersal and recruitment of coral reef fishes.

S. Shuttleworth1and S. Thorrold2, 1Washington University of St. Louis, and 2Old DominionUniversity. High-resolution spatial sampling of the trace element chemistry of otoliths usinglaser ablation magnetic sector ICPMS.

R. Thresher, B. Bruce and C. Proctor, CSIRO Division of Marine Science, Australia. Directmeasurement of rates of larval exchange among populations of the temperate shelf fish, Nemadactylusmacropterus, based on larval distributions and analysis of otolith composition.

For more information on the Symposium, contact Simon Thorrold (thorrold@estuary.amrl.odu.edu)

12

(combined) on the larval performance variables thatwere measured. This result conforms with thosereported by Ouellet (see Ouellet’s report above, andDutil et al. 1998): for 1995 there were only weakeffects of maternal condition and thermal history onthe egg quality variables measured. There are anumber of likely explanations for the lack of a moreconsistent effect: the fact that the majority of egggroups that we followed were the progeny of femaleswith relatively high pre-spawning condition factors;the relatively small range of pre-spawning conditionfactors for these females; the fact that we wereunable to follow the full complement of egg groups.

The relationship between larval SGR, over-all activity and swimming speed were also evalu-ated. With only one exception (dry mass vs. larvalactivity at 3 DPH), all of these were significant:there were direct relationships between larval SGRand both activity and swimming speed. The signifi-cant positive relationships between larval SGR andactivity or swimming speed support the use of thesevariables as reasonable indicators of larval perfor-mance.

Albeit tentative, these results represent oneof the first demonstrations of a link between femalecondition and the performance of her progeny. Thecondition factors of the females for which eggbatches were followed in 1996 were considerablygreater than those for 1995 and included more egg

groups from those in poor condition. We are hopefulthat this will allow us to discern more conclusiveeffects of maternal condition and spawning historyon larval performance. We will also determine, for1995 and 1996, whether there is any relationshipbetween the larval performance variables that wemeasured and post-spawning female condition fac-tor.

2.) The impact of ultraviolet radiation on marinezooplankton and ichthyoplankton: radiometry, at-tenuation coefficients, mortality effects, bio-logical weighting functions and DNA damage.

Over the past 10 - 15 years, levels of solarultraviolet-B radiation (280-320 nm, UVB) incidentat the Earth’s surface have increased significantlyover mid-latitude areas of the Northern and South-ern Hemispheres. These increases in UVB are linkedto reductions of stratospheric ozone.

A growing number of studies indicate thatUVB radiation, at current levels, is harmful toaquatic organisms and may reduce the productivityof marine ecosystems. Such UV-induced reductionsin productivity have been reported for phytoplank-ton, heterotrophs, and zooplankton, the key interme-diary levels of marine food. Analogous studies onfish eggs and larvae, although rare, indicate thatexposure to levels of UVB currently incident at theEarth’s surface results in higher mortality that maylead to poorer recruitment to adult populations.

(Continued from page 9)

Attention students going to Ann Arbor!! The ELHS announces the availability of two (2) travel grants, each for $300.00, to provide assistance forstudent travel to the Annual Larval Fish Conference in Ann Arbor, MI. Applications for grants must include 1) aletter of request from the student; 2) a copy of the abstract of the paper to be given by the student in Ann Arbor;and, 3) a letter of recommendation from the student"s major professor or faculty advisor indicating that the stu-dent is in good standing and in need of support to attend the Annual Larval Fish Conference. Student applicantsmust be members of the ELHS. Based upon the above criteria, grants will awarded by committee decision.

Send completed applications by the deadine for abstract submission to the 22nd Annual Larval FishConference to:

Dr. Jim CowanDauphin Island Sea Lab

P.O. Box 369-370Dauphin Island, AL 36528

For further details, contact Jim at (334)-861-7535 or by Email at jcowan@jaguar1.usouthal.edu

January 1998

In some regions of the Gulf of St.Lawrence, Canada, the late spring and summerwater column shows a pronounced thermocline be-tween 10 and 30 m. A cold intermediate layer (-1 to+1 °C), situated at depths of 30 - 100 m andcomposed of relatively fresh water, separates thewarm mixed layer near the surface (14 - 16 °C insummer) from the waters at depth (6 °C). As aresult of the spring-through-fall presence of thisintermediate cold layer, the most important(productivity-determining) biophysical interactionsoccur in the upper 10 to 30 m of the water column.During summer, the mixed layer in these waters canbe as shallow as 10 m. The eggs and larvae ofseveral commercially important marine inverte-brates and fishes are found in this layer.

Measurements of the diffuse attenuationcoefficients for solar UVB at various locations inthe estuary and Gulf of St. Lawrence indicate maxi-mum 10% depths (the depth to which 10% of thesurface irradiance penetrates at a given wavelength)of three to four meters at a wavelength of 310 nm(Kuhn et al. 1998). This represents a significantpercentage of the summer mixed-layer water col-umn. In clear tropical ocean waters the 10 % depthat 310 nm can be as deep as 15 m. UVB-induceddamage to the DNA of fish eggs and larvae has beendetected in samples collected from depths of up to20 m. Thus, the early life history stages of thecrustacean and fish species that are present in theshallow mixed layer of the water column may beparticularly susceptible to increasing levels of UVB.

The reproductive season for Atlantic cod(Gadus morhua) in the Gulf of St. Lawrence beginsearly in the spring and continues through late June.Spawning occurs in deep water (> 200 m) and codeggs, which are typically positively buoyant, ascendto the surface mixed layer over a period of two toten days. A significant proportion of all cod eggspresent in the water column occur in the 0 - 25 mdepth stratum off the Newfoundland, off Greenlandand Labrador, on southern Georges Bank and in thenorthern Gulf of St. Lawrence. On clear summerdays, when wind speed is low, the highest eggconcentrations are observed near the surface. Theearly larval stages are also typically present in thesurface layer.

Following from the hydrographics of thisregion, and given the planktonic character of theearly life stages of cod and many other fish andcrustacean species, this system offers an appropriateopportunity to assess the impacts of solar UVBradiation on temperate-latitude marine ecosys

Within this context , we investigated poten-tial impacts of UVB radiation on the early life stagesof cod. The goals of this study were to 1) evaluatethe effect of UVB radiation on mortality in the eggsof cod and determine whether developmental stateaffects susceptibilty to UVB, 2) generate dose-response relationships and test the principle of re-ciprocity, which states that the UVB-induced mor-tality effect on cod eggs will be dose but not doserate dependent, 3) derive a biological weightingfunction (BWF) for the effect of UVB on mortalityin cod eggs, and 4) present a preliminary assessmentof the potential impact of solar UVB on the early lifestages of cod in the subarctic marine ecosystems ofeastern Canada.

Laboratory experiments using a xenon arclamp-based solar simulator revealed that cod em-bryos were highly susceptible to UVB, resulting inhigh wavelength-dependent mortality. The strongesteffects occured under exposures to wavelengthsbelow 312 nm. This susceptibility was also depen-dent upon developmental stage; mortality was par-ticularly high during gastrulation. At the shorterwavelengths (< 305 nm) UVB-induced mortalitybegan at unweighted cumulative doses of approxi-mately 1000 kJ m-2 and was strongly dose-dependent with 100 % mortality occuring at dosesnear 15000 kJ m-2. Dose-dependence of UVB-induced mortality was not significantly influencedby dose-rate. The biological weighting function(BWF) derived for UVB-induced mortality in codeggs is similar to that reported for naked DNA.This suggests that the UVB-induced mortality effecton cod embryos is a direct result of DNA damage.This contention is further supported by an experi-ment - conducted in collaboration with Russell Vet-ter at the NOAA-NMFS laboratory in La Jolla - onDNA damage in cod embryos exposed to UVBradiation. Results from this experiment showed thatdamage to the DNA of cod embryos was signifi-cantly higher than control groups (held in the dark)

14

only at wavelengths below 320 nm.Calculations based upon the BWF indicate

that, under current noon surface irradiance, 50% ofcod eggs located at or very near the ocean surfacewill be dead after 42 h of exposure. Under solarspectral irradiance simulating a 20% decrease inozone layer thickness, this time drops to 32 h. Theseare first-order estimates based upon irradiance takenat a time of day during which the values would bemaximal. Nonetheless, they illustrate the relativechanges in UVB impacts that will result from ozonelayer depletions expected over the coming decades.

3.) Predatory behaviour of Paraeuchaetanorvegica feeding on Atlantic cod (Gadus morhua)larvae

In collaboration with Jeannette Yen (StateUniversity of New York, Stony Brook), and using asilhouette video optical system, we made the firstever direct observations of the predatory feedingbehaviour and attack sequence of Paraeuchaetanorvegica, a carnivorous copepod, feeding on yolksac stage Atlantic cod larvae. P. norvegica perceivecod larvae using their tactile sense. As a result,location distances are small and the cod larva mustbe moving to be perceived. As a result of these smalllocation distances, encounter rates will be low. At-tack speeds were extremely high: much higher thanthe escape velocities of which cod larvae are capa-ble. P. norvegica requires approximately 10 min. toconsume an entire cod larva.

4.) Relocation to Norway and work thereSome STAGES readers will already know

that I will be relocating to Norway in March 1998 totake up a research position with the Institute ofMarine Research. I will be a member of a groupstudying the biology and ecology of early life stagesand intend to develop several lines of research thatfollow from those on which I have been workingover the past 15 years. Stay tuned.

For more infomation on any of Howard’sresearch, please contact him at:

Dr. Howard I. BrowmanInstitute of Marine Research

Aquaculture Centre

Austevoll Aquaculture Research StationN-5392 Storebø, NORWAY

Office telephone: 47 56 180 347 (Press 113 afterthe triple tone)

Main switchboard (where messages can be left)telephone: 47 56 180 342Facsimile: 47 56 180 398

Email: howard.browman@imr.no

Recent publications from Howard Browman’s labBrowman, H.I. 1996. Effets des UVB sur les ressourcesmarines. Canadian Meteorological and Oceanographic Soci-ety Bulletin 24 (1): 1-2.

Browman, H.I. 1996. L’augmentation du rayonnement ultravi-olet B peut-elle avoir des incidences négatives sur lesressources marines dans le golfe du Saint-Laurent? Le Natu-raliste Canadien 120: 66-68.

Browman, H.I. 1996. Predator-prey interactions in the sea:commentaries on the role of turbulence. Marine EcologyProgress Series 139: 301-302.

Browman, H.I. & A.B. Skiftesvik. 1996. The effects of turbu-lence on the predation cycle of fish larvae: comments on someof the issues. Marine Ecology Progress Series 139: 309-312.

Vaughan, H., J. Carey, R. Bukata, H. Browman, M. Morrison,K. Percy, R. Robarts and F. Crisp. 1997. Addressing theEcosystem Effects of Ultraviolet Radiation Including an In-ventory of Research and Collaborative Mechanisms: Report ofthe Working Group on the Ecosystem Effects of UltravioletRadiation convened under the Memorandum of Understand-ing on Science and Technology for Sustainable Developmentin the Natural Resources Sector. Government of Canada,Environment Canada, National Water Research Institute,Burlington, Ontario, 77 p.

Dutil, J.-D., M. Castonguay, M.O. Hammill, P. Ouellet, Y.Lambert, D. Chabot, H. Browman, D. Gilbert, A. Fréchet.J.-A. Gagné, D. Gascon & L. Savard. 1998. Environmentalinfluences on the productivity of cod stocks: some evidencefor the northern Gulf of St. Lawrence, and required changes inmanagement practices. Department of Fisheries and Oceans(Canada). Atlantic Fisheries Research Document 98/18: 42p.

Kouwenberg, J.H.M., H.I. Browman, J.J. Cullen, R.F. Davis,J.-F. St-Pierre & J.A. Runge. Biological weighting ofultraviolet-B induced mortality in marine zooplankton andfish. I. Atlantic cod (Gadus morhua) eggs. Marine Biology(submitted).

Kouwenberg, J.H.M., H.I. Browman, J.A. Runge, J.J. Cullen,R.F. Davis, J.-F. St-Pierre. Biological weighting ofultraviolet-B induced mortality in marine zooplankton andfish. II.Calanus finmarchicus eggs. Marine Biology(submitted).

Kuhn, P., H.I. Browman, B. McArthur & J.F. St-Pierre. The

January 1998

penetration of ultraviolet radiation in the waters of the estuaryand Gulf of St. Lawrence. Limnology and Oceanography(submitted).

Béland, F. & H.I. Browman. The effect of solar ultravioletradiation on Atlantic cod eggs. Canadian Journal of Fisheriesand Aquatic Sciences (in preparation).

Browman, H.I., Alonso Rodriguez, C., Béland, F., Cullen,J.J., Davis, R.F., Kouwenberg, J.H.M., Kuhn, P., McArthur,B., Runge, J.A., St.-Pierre J.-F. & Vetter, R.D. The impact ofultraviolet radiation on marine zooplankton and ichthyoplank-ton: radiometry, attenuation coefficients, mortality effects,biological weighting functions and DNA damage. Verhand-lungen Internationale Vereinigung für theoretische und ange-wandte Limnologie (in preparation).

Browman, H.I., R.D. Vetter & C. Alonso Rodriguez. UV-Binduced DNA damage in Atlantic cod (Gadus morhua) andCalanus finmarchicus embryos. Marine Biology (in prepara-tion).

Yen, J. & H.I. Browman. Direct observations of the foraginginteractions between the predatory copepod araeuchaetanorvegica and Atlantic cod (Gadus morhua) larvae. Journalof Plankton Research (in preparation).

16

Southern Region - Jon Hare,NOAA / NMFS, BeaufortLaboratory, 101 Pivers IslandRoad, Beaufort, NC 28516.

(Phone: (919) 728-8732; Email:jhare@hatteras.bea.nmfs.gov).

Department of Biological Sciences, Univer-sity of South Alabama, Mobile

Judith Shardo, formerly at the University ofMassachusetts, is continuing her research on thecomparative embryology of teleost fishes at theUniversity of South Alabama. Using scanning elec-tron microscopy (SEM), Judith produces detaileddescriptions of morphological development in teleostembryos and larvae. Morphological ontogenies ofextant teleosts are the result of adaptive and evolu-tionary changes modifying the ancestral develop-mental pattern. Comparisons of patterns of devel-opment among descendant species of a commonancestor can be used to reconstruct the history ofchanges and adaptations in teleosts. The initial stepis to devise a comparative staging system that isable to identify comparable levels of development inembryos of very different species, essentially homol-ogous stages. Each stage of the system is defined byone or two morphological criteria that arewidespread fundamental features of teleostean de-velopment. The number of criteria defining a stageis limited because developmental rates of differentembryonic structures often times vary within aspecies, so that a group of morphological featuresthat characterize a stage in one species may bedispersed among several stages in a differentspecies. All developmental features other than thecriteria defining the stage are treated as concurrentfeatures that are not necessarily coupled to thedefining criteria of that stage and thus may show achange in the timing of their appearance in differentspecies. Age or size as a measure of development,are generally not comparable among species and aretreated as concurrent features.

Judith devised an initial staging systembased on American shad (Alosa sapidissima) devel-opment and is now using data on Atlantic salmon

(Salmo salar) development to modify the system.Preliminary comparisons of homologous stages inthese two species indicate distinct differences in gilland opercular formation, and in the overall level ofmorphological development at hatching. Studies areneeded to determine the possible adaptive signifi-cance of these differences. Recent NSF support willallow expansion of the study and several species,including the bay anchovy (Anchoa mitchilli) andchannel catfish (Ictalurus punctatus), will be addedthis year.

Andrew Woodard, an undergraduate stu-dent working in Dr. Shardo’s lab, is in the processof applying the morphological staging system toembryonic and larval red snapper (Lutjanuscampechanus). Samples were collected at the Al-abama Marine Resources facility in Gulf Shores.Red snapper will be the first marine species to becompletely categorized by this staging system. An-drew is using both light microscopy and SEM todescribe the development of this species. Red snap-per have small eggs (0.72mm) and different tech-niques had to be devised to physically manipulatethe eggs and critical point dry specimens for exami-nation with SEM. Chemical drying agents havebeen used with some success on the early embryonicstages, while work continues on improving methodsfor drying the post hatch specimens.

For more information please contact

Judith ShardoDepartment of Biological Sciences

LSCB 124University of South Alabama

Mobile, AL 36688E-mail jshardo@jaguar1.usouthal.edu.

January 1998

Pacific Rim Region - IainSuthers, School of BiologicalSciences, University of NewSouth Wales, Sydney, Aus-

tralia. (Phone: +61 2 385-2065; E-mail: I.suthers@unsw.edu.au).

Report from south-eastern Australia

Everyone is away right now, after theirsuccessful Australian Research Grant foraging tripslast year. Both Jeff Leis (Australian Museum) andMike Kingsford (University of Sydney) scored 3year grants to examine larval behaviour aroundtropical reefs, and right now is peak larval produc-tion time. Mike has just returned from a 3 monthstudy leave in Spain, and now has another 3 monthsin New Zealand, where one of his objectives is tocomplete a book on techniques in coastal ecology.

Iain Suthers spent 7 months working inBergen and Rekjavik (finishing up more neat codgrowth histories), before settling in at DalhousieUniversity in Halifax, Canada with Chris Taggart,working up plankton particle size distribution datain various shallow and deep island wakes from theGreat Barrier Reef. We collected 38 families ofneustonic larval fish while we towed an opticalplankton counter, and found two groupings of larvaltaxa correlated with either "small" (300-500 µmdiameter bugs found near the surface) or "medium"zooplankton (500-1200 µm bugs usually found nearthe bottom, except where there was tidal stirring anduplifting). The plankton distribution was seen toevolve during both flood tides that we examined,resulting in a 3-4 fold concentration of zooplanktonby the end of the tide, about two island diametersdownstream. The average concentration of larvalfish (300 per 250 m3), with an equivalent sphericaldiameter between 2,500-5,000 µm, fitted neatlyonto that predicted from the exrapolated size spec-trum of zooplankton! Around other reefs, we foundzooplankton concentrated in zones of low tidalflushing, as predicted by oceanographic models.The size distribution of zooplankton biomass is nowbeing examined as a measure of production, inrelation to recent otolith growth.

Iain also worked at the Bedford Institute ofOceanography, examining the increment width se-ries of the otolith as a means of calibrating somelarval condition indices with actual back-calculatedgrowth. A number of larval species (Australianbass, and snapper, Pagrus auratus), along withAtlantic cod, show a rapid response in incrementwidth to feeding and starvation events - but thereseems to be a size dependency! The full story willbe told at the 2nd World Otolith symposium inBergen - hope to see you all there.

The 3rd International Larval Biology Con-ferenc

This conference was held in Melbournefrom January 13 to 16, 1998. There was a goodrepresentation of larval fish talks, especially in thesymposium "Larval behaviour: is it important todispersal and recruitment?". A number of talksconcentrated on the dispersal and recruitment ofcoral reef fish while talks on temperate species werealso well represented. Invited speakers in this sym-posium with fish related talks were Dick Forward,Peter Doherty, Jeff Leis and Greg Jenkins (togetherwith Alan Shanks, Edwin Bourget, Ib Svane andDick Zimmer-Faust talking about invertebrates).Other mini-symposia were: "Evolution of LarvalForm", "Chemical Ecology" and "Larval Nutrition",together with a large number of general sessiontalks. As with the first two conferences, this meetingprovided an opportunity for larval fish and inverte-brate workers to "cross-pollinate" ideas and wasenjoyed by all. The 4th meeting is scheduled forCalifornia in 1999.

For more information on this meeting,please contact:

Dr Greg JenkinsQueenscliff Marine Station

P.O. Box 138Queenscliff, Victoria 3225

AustraliaPh: +61 3 52583686Fax: +61 3 52583632

Email: g.jenkins@msl.oz.au

18

MEETING REVIEWS

21st Annual Larval Fish Conference

The 21st annual Larval Fish Conference ofthe Early Life History Section (ELHS) of the Amer-ican Fisheries Society was held in conjunction withthe 77th annual meeting of the American Society ofIchthyologists and Herpetologists 26 June-2 July,1997, on the campus of the University of Washing-ton (UW) in Seattle, Washington. More detailsabout the meeting can be found at the meetingwebsite: http://artedi.fish.washington.edu/asih/asih97.html. Among the over 1700 participants inthe meetings, about 188 registered for the LarvalFish Conference. Bill Rugen, AFSC, designed themeeting logo, and several items with the logo wereavailable for sale during the meeting includingT-shirts, insulated travel mugs, and chocolatemedallions.

The poster session included 28 entries. Theposter session finale was a reception sponsored byResearch Nets, Inc.

A banquet for the EHLS participants tookplace on Monday evening. Dr. Milton Love pro-vided a highly entertaining banquet address remind-ing us of why we became biologists, and why westudy fishes. Another highlight of the banquet wasthe presentation of an award of appreciation tolong-time active ELHS member, Gail Theilacker.

The Sally L. Richardson Award was pre-sented during the EHLS banquet for the best studentpaper given at the Larval Fish Conference. Therewere 32 entries in the competition this year, thehighest number ever. This year=s award was shared

by two co-winners Jennifer Caselle-Reinhardt(University of California, Santa Barbara) for thepresentation “Density dependent earlypost-settlement mortality in a coral reef fish and itseffect on local population size” which was givenduring the juvenile symposium, and Ulrich Rein-hardt (University of British Columbia) for the pre-sentation “Size-dependent foraging behaviour anduse of cover in juvenile coho salmon under predationrisk” which was given in the salmon symposium.Co-honorable mention went to Jay Rooker(University of Texas, Austin) and Jason Rogers(University of North Carolina). The Richardsonraffle attracted over 50 excellent items, and gener-ated $1000 for the award fund. The drawings forthe raffle occurred during the ELHS banquet duringwhich Clark Hubbs greatly expanded his wardrobeof fish related T-shirts and hats.

Oral sessions and symposia began on Fri-day afternoon with a keynote address by Dr. GeorgeBoehlert who spoke on AEarly life history: Is it thekey to understanding fish population processes?@ Atotal of 90 oral presentations followed over the nextfive days, as the LFC part of these meetings. Addi-tionally, a number of papers of interest to peopleworking on early life history were also given in othersessions of the ASIH meetings.

Three symposia were held during the meet-ing. Highlights of each symposia follow.Juvenile Fish Studies: Contributions toEarly Life History and Recruitment Pro-

The 21st Larval Fish Conference in Seattle was a great success. The LFC is the Sec-tion’s principal meeting each year. It is a great opportunity to hear what is going on at thecutting edge of our field, make new friends and meet existing ones. However, it is impossiblefor all ELHS’ers to attend the conference. In an attempt to ensure that everyone gets an ideaof the flavour of the meeting STAGES will carry a rewiew of each conference. In the pagesthat follow Art Kendall and Ann Matarese with input from Morgan Busby, Ric Brodeur,Francis Juanes, and Darrel Snyder, provide their perspective of the events in Seattle

January 1998

cesses (organized by Ric Brodeur andBrenda Norcross):

From the very beginning of early life historyand recruitment studies, most of the emphasis hasbeen on the egg and larval periods as being thecritical stages, with the later post-metamorphicstages being virtually ignored. For many fishspecies, especially those subject to heavy predation,it has become apparent that substantial interannualvariability in survival can occur in the juvenilestage, and for these species this stage may be amissing link in recruitment studies. Many recruit-ment programs now advocate a more balanced ap-proach examining survival mechanisms right up tothe time of recruitment. In species which settle outof the plankton and, particularly those which mayhave certain habitat requirements such as flatfishesand reef fishes, many studies have showdensity-dependent growth or survival in juvenileswhich has not often been observed in larvae. In somespecies, the biomass of a particular cohort actuallypeaks during the juvenile stage and this, coupledwith their high growth and turnover rates, makesjuvenile fishes an important trophic link both aspredator and prey in many ecosystems. This sym-posium was an attempt to fill in some of the gaps inour understanding of early life history and recruit-ment in the juvenile stage.

The symposium consisted of a main sessionof eight invited speakers followed by two con-tributed sessions consisting of 18 oral presentations.There were also a number of posters dealing withthis topic. Dr. Susan Sogard from the HatfieldMarine Science Center in Newport, Oregon was thefirst invited speaker and presented a stimulatingpaper on "Size-selective mortality in the juvenilestage of teleost fishes: A review". Dr. Robin Gibsonof the Dunstaffnage Marine Laboratory in Scotlandpresented an overview of his work entitled"Movement patterns of juvenile plaice: balancingfeeding opportunity and predation risk". Dr. GregJenkins and coworkers of the University of Mel-bourne, Australia, next presented their findings on"Factors influencing recruitment of a demersal fishto seagrass beds in a temperate bay". A moretropical example entitled "Neglected variations injuvenile nursery habitat: the Hawaiian pink snapper

as an example" was presented by Ed DeMartini ofthe NMFS Honolulu Lab. Dave Conover ofSUNY-Stony Brook presented many years of workby he and his collaborators in the next paper"Advection, piscivory, and estuarine-dependency:the role of early juvenile stages in recruitment of thebluefish, Pomatomus saltatrix". Steve Ralston ofthe NMFS Tiburon Laboratory provided anoverview of his research on "Interannual variabilityand coherence among the pelagic juvenile rockfishesof Central California". Dr. Yoshiro Watanabe ofthe Ocean Research Institute in Tokyo next pre-sented a more oceanic perspective in his paper"What determines juvenile production of saury inthe Kuroshio-Oyashio waters: larval production orearly mortality?". In the final invited talk, JimCowan and coworkers provided an interesting modelapplication to study the importance of the juvenilestage in their presentation "Cohort biomass, preyconsumption and density-dependence during on-togeny of marine fishes: a case study of bay an-chovy". Both the invited and contributed sessionswere well attended and all speakers are to be com-mended for their outstanding talks in this, the firstELHS symposium on juvenile fishes.

Ontogeny of North Pacific ScorpaeniformFishes (organized by Morgan Busby andDavid Ambrose):

This symposium was comprised of fivetalks on sculpins (family Cottidae) and two onrockfishes (family Scorpaenidae, genus Sebastes).Danny Kent of the Vancouver, B.C. Public Aquar-ium opened the symposium with an very interestingtalk on interspecific nesting in marine fishes: AS-pawning of the spinynose sculpin Asemichthys tay-lori on the eggs of the buffalo sculpin Enophrysbison@. Enzo Acua followed with a talk on larvaldevelopment of the red rockfish off Northern Chile.Deborah Blood from NOAA=s Alaska Fisheries Sci-ence Center then spoke on identification and devel-opment of Triglops larvae from both the NorthPacific and Atlantic Oceans. Amy Cook from U.C.Irvine followed with the first student presentationentitled AOntogeny of Skull Morphology in CottidFishes@ - which focused on some interesting differ-ences in shape and growth characteristics between

20

ram and suction feeding sculpins throughout devel-opment. The following talk, also focusing on cot-tids, was given by Rick Feeny of the Los AngelesCounty Museum, and titled ANear Shore Distribu-tion of and Abundance of Sculpin Larvae(Scorpaeniformes: Cottidae) in the Southern Cali-fornia Bight@. Fumihito Muto, a doctoral student atthe Hokkaido University Laboratory of Marine Zo-ology, spoke on the identification and comparison ofmorphological development of early stages of fishesof the genus Myoxocephalus (Teleostei: Cottidae)from Japan. The final presentation was given byCindy Taylor, a student from San Diego StateUniversity on her study that is being conducted inconjunction with scientists from NOAA=s SouthwestFisheries Science Center entitled ALarval Identifica-tion of Rockfishes (genus Sebastes) using mitochon-drial DNA Techniques@. The symposium was wellattended and all speakers did an outstanding job ontheir presentations.

Habitat use and diel activity patterns in ju-venile salmon: comparisons of Atlantic andPacific species (organized by Francis Juanesand Scott Hinch)

There has been much emphasis on habitatuse of stream-dwelling salmonids, only more re-cently has that work extended to juvenile stages ofAtlantic (Salmo salar) and Pacific salmon(Oncorhynchus spp.). A clear understanding ofhabitat use patterns is critical as stream habitatscontinue to change necessitating intervention andrestoration. However, we still know relatively littleabout macrohabitat selection and ontogenetic shiftsor diel patterns in habitat use. The hope was thatthis session would bring together researchers focus-ing on these less-well described aspects of habitatuse and focusing on recent approaches that includeenergetics and individual-based modeling.

The session attracted 8 talks, 6 on Pacificsalmon and 2 on Atlantic salmon. Four of the talkswere presented by graduate students. The sessionbegan with three talks describing work at the Uni-versity of British Columbia. The first by ScottDecker and Scott Hinch entitled "Seasonal changesin juvenile coho salmon biomass from groundwaterside channels: the role of fish size and primary

production," the second by Guillermo Giannico andScott Hinch entitled "The effects of woody debrisaddition on movement in and out of groundwater fedside-channels by juvenile coho salmon during win-ter," and the third by Ulrich Reinhardt and MikeHealey entitled "Size-dependent foraging behaviourand use of cover in juvenile coho salmon underpredation risk." Ulrich went on to share theRichardson award for best student presentation. Thenext two talks focused on habitat use by juvenilesalmonids in Washington State and Oregon. Thefirst by Lauri Freidenburg, Gilbert Pauley and JohnEmlen entitled "Habitat use of juvenile salmonids:the effects of scale and method of habitat assess-ment," the second by Mario Solazzi and co-authorsentitled "Habitat Use by Juvenile Salmonids in Ore-gon Coastal Streams." The next two talks focusedon daytime sheltering of juvenile Pacific and At-lantic salmon in British Columbia and Vermontrespectively. Paul Higgins and Mike Bradford pre-sented a talk entitled "The role of photoperiod,temperature and food availability on daytime con-cealment behaviour of juvenile Pacific salmon," andGabe Gries and Francis Juanes (presented byJuanes) spoke on "Microhabitat use by daytimesheltering juvenile Atlantic salmon during summer."Finally, Keith Nislow and Carol Folt summarizedtheir energetic-based approach in a talk entitled"Supply and demand in the study of habitat suitabil-ity for first-year stream salmonids." The talks wereall presented very professionally (particularly thoseby students) and appeared to address commonthemes. It was clear that researchers working onboth Atlantic and Pacific salmon are asking similarquestions and that future interactions would befruitful. The session was well-attended. For moreinformation, please contact :

Francis JuanesDepartment of Forestry and Wildlife

Univeristy of Massachusetts - AmherstAmherst, MA 00000

Phone: (413) 545-2758Email: juanes@forwild.umass.edu

or any of the other speakers if you have anyquestions or comments.

Three workshops were also held in associa-

January 1998

tion with the meetings:

Larval Identification:This workshop, orgainized by Morgan

Busby, provided an opportunity for people to bringsamples of unknown fish larvae and receive helpidentifying them. Microscopes were available forviewing specimens, and a wide assortment of litera-ture was on hand. A video setup allowed simultane-ous group observation of specimens. Collectionsfrom several parts of the world were examined in aninformal setting. About 50 people attended all orpart of this 2-hour workshop.

Preservation and Curation of Early LifeStages of Fish, Amphibians, and Reptiles:(Organized by Alexandra M. Snyder of theMuseum of Southwestern Biology, Univer-sity of New Mexico, and Darrel E. Snyder ofthe Larval Fish Laboratory, Colorado StateUniversity):

This workshop on problems, concerns, andtechniques related to the preparation and care ofpreserved early life stage collections was jointlyconvened on behalf of the American Society ofIchthyologists and Herpetologists (Collections Com-mittee) and ELHS Larval Fish Conference. Theafternoon workshop was divided into three sessions:(1) elasmobranch, amphibian, and reptilian early lifestages; (2) teleost early life stages; and (3) an openforum. Attendance varied according to topics ofinterest but at times was standing room only. Pre-sentation abstracts are being prepared for the ASIHCuration Newsletter and both the ASIH and ELHSwebsites (http:// www.utexas.edu/depts/asih/, Cura-torial Information; http:// www.cnr.colostate.edu/~desnyder/elhshome.htm, Conferences, Symposia,and Workshops).

Lex Snyder opened the workshop with awelcome introduction and a discussion of the need toproperly document the preservation and preparationhistory of specimens from original fixation andpreservation on field notes through subsequentpreparation and changes in preservative as the col-lections are processed and accessioned. Shestressed the importance and value of "accessionfiles" for maintaining this and related collection

documentation.The first session opened with a presentation

on the "collection of reptilian embryos: methods,standards, and ethics" by Alan H. Savitsky (OldDominion University; co-author, William A. Velha-gen, Jr., James Madison University). Alan notedthat this is a neglected area of biodiversity samplingand discussed the special procedures, preservatives,and concerns required to obtain quality preservedembryos from oviparous and viviparous species.Steven W. Gotte (USGS-BRD, National Museum ofNatural History; co-author, Robert P. Reynolds)continued with a paper on tadpole preservationtechniques and their "observations on the effects ofalcohol versus formalin storage of amphibian lar-vae." Noting the world-wide decline in amphibianpopulations, he emphasized the importance ofwell-preserved larvae for accurate identification;larvae are often the only life stages accessible duringfield investigations. Currently recommended prac-tice is to fix and maintain specimens in 10%buffered formalin rather than transfer them to 70%ethanol. The session concluded with an overview oftechniques for "preservation of embryonic and fetalelasmobranch tissues" by Madeline Oetinger(Kentucky Wesleyan College).

Grace Klein-MacPhee (University of RhodeIsland) opened the teleost session with a presenta-tion entitled "The trouble with ctenophores: ichthy-oplankton preservation problems." Ctenophores inichthyoplankton collections coalesce into "blobs" ofmaterial which not only make sample sorting diffi-cult but readily absorb formaldehyde often leavingfish eggs and larvae in poorly fixed condition; like-wise for oil in collections for oil-spill areas. To helpassure dequate fixation, Grace recommended rins-

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22

ing samples well with as many as four changes ofthe preservative. David G. Smith (National Mu-seum of Natural History; co-author Carole C.Baldwin) followed with a slide show on and discussof "color in larval fishes: occurrence, importance,and preservation." Color patterns, especially fromred and yellow chromatophores, can be valuablediagnostic characters but rapidly fade and are nor-mally lost in formalin and alcohol-preserved larvae.David explained that they've had considerable suc-cess in using the antioxidant BHT to retain colorfor at least several months and also recommendedrecording color patterns by photographing freshlycollected larvae.

Darrel continued the session by brieflyreviewing the contents of "a list of larval fishcollections" he was preparing for the workshop andASIH and ELHS web sites and newsletters. At thetime the list covered about 40 collections fromNorth, Central and South America, Europe, andAustralia, with many more to be abstracted from adatabase on U.S. and Canadian fish collectionsassembled by Stuart Poss and Bruce Collette (seeCopiea 1995:48-70). Records include name andcontact information for the host organization andresponsible persons, permanency, size, nature, geo-graphical coverage, and catalog status of the col-lections.

The final three papers dealt with the effectsof preservation or preparation techniques on thelengths of fish larvae. Jennifer M. Bayer(USGS-BRD, Columbia River Research Labora-tory; co-author Timothy Counihan) reported on"length changes in white sturgeon (Acipensertransmontanus) larvae: effects of ethanol and for-

malin." After 95 days in preservative, they foundan average of just 0.4 to 1.0% shrinkage for 1 and7-d old larvae in 10% formalin but 2.4 to 3.4%shrinkage for 14-d old larvae in 10% formalin andall three age-groups in 95% ethanol. John. F.Dower (Queens University, Ontario; co-authorWilliam Leggett, same; first author Pierre Pepin,Fisheries & Oceans, St. John's) discussed "changesin the distribution of larval fish body length follow-ing preservation" with formalin for the wild-caughtlarvae of nine coastal species. They found signifi-cantly increased post-preservation length for indi-viduals initially up to 6 mm standard length, de-creased length for those initially greater than 7 mm,and increased variation of length about the mean(for each 1-mm initial size interval) which alsoincreased with increasing initial size. Finally "theeffects of clearing and staining on fish length" wasaddressed by Edward S. Warren (San Diego StateUniversity; co-authors Eron Aldridge and PaulaMabee). For Tilapia initially 6 to 62 mm standardlength, fixed in 10% buffered formalin, then trans-ferred to 70% alcohol, they found that clearing andstaining for bone and cartilage caused significantshrinkage which increased with initial size.

Questions or comments regarding theabove and other topics were discussed during theopen forum. One topic of particular interest tomany participants was the possible use of plastina-tion (polymer impregnation) as a dry, odorless, anddurable alternative to maintenance fish larvae influid preservatives, especially for heavily used ref-erence and study series. Darrel briefly discussedthe process which is used for medical school cadav-ers and displayed a few sets of larval fish speci-

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January 1998

mens (one with larvae just 4 to 5 mm in total length)that were plastinated experimentally for this work-shop by William D. Martin (West Virginia Schoolof Osteopathic Medicine).

Application-specific Computer Image Anal-ysis (Convened by Darrel E. Snyder of theLarval Fish Laboratory, Peter Hagen of theAlaska Department of Fish and Game, Mor-gan S. Busby of the NMFS Alaska FisheriesScience Center, and Craig Pfaff, DennisKaill, Straton Spyropoulos, and ChristianErbe of Optimas Corporation):

Use of computer image-analysis techniquesin the study of fishes and fishery resources issteadily increasing and diversifying. The benefits ofsuch techniques in investigations of the early lifestages of fish are particularly promising, but thereremain many limitations and problems, and some-times just a lack of "know-how." This all-day eventwas intended to address some of the limitations,problems, and solutions for three specific applica-tions related to work with early life stages of fishesthrough a pre-workshop session, consecutive work-shops dealing with each of the three applications.Each workshop consisted of three sessions: formalpresentations, open computer, and open forum. Theopen computer sessions (combined for the smallersecond and third workshops) provided opportunitiesfor individual or small group hands-on experience,demonstration, and experimentation, as well as theexchange of programs, utilities, and macros. Theopen forums (also combined for the second and thirdworkshops) provided opportunities to address ques-tions remaining after the formal presentations aswell as additional concerns and matters not coveredby those presentations. Despite the event being heldat a remote location, the Western Regional Center ofthe NOAA National Marine Fisheries Service(transportation provided from and back to the Uni-versity), and on the final day of the conference(otherwise reserved for field trips), over 80 personsparticipated, including several from overseas. Theworkshops were open to all interested persons buttargeted those with at least some computerimage-analysis experience. Attendees were asked tobe prepared to discuss related problems they'd expe-

rienced in applying image analysis to their investiga-tions, share their solutions to problems, and demon-strate and exchange useful (public) programs,macros, or approaches they developed or refined.Although some techniques or approaches presentedand discussed in these workshops were necessarilyspecific to Optimas or other image analysis pro-grams, whenever possible, discussions were genericand directed towards image analysis in general.Printed handouts complemented several presenta-tions. For presentations and use during the openforums, Optimas and other programs were installedon a computer connected to a display projector. Tencomputers were setup in a separate room for thescheduled open computer sessions and for use dur-ing breaks. A complete image-analysis system withframe grabber and camera connected to a dissectingmicroscope was also available.

Darrel Snyder opened the event with a gen-eral welcome, review of the day's agenda, and recog-nition of co-conveners and others that made theevent possible. The pre-workshop session whichfollowed was presented by Straton Spyropoulos andprovided a brief introduction to image analysis andsome of the procedures and tools useful to all threeof the subsequent workshops. Macros and imageenhancement were emphasized.

The first and largest workshop, Otolith,Scale, and Related Analyses, was lead by Peter andintended to cover recovery of age, growth, and otherinformation (e.g., tags, stock identification) from theotoliths, scales, or other bony structures of larvaland juvenile fishes. Peter introduced the workshopby recounting the history of this image-analysisapplication. Simon Hickinbotham (University ofYork, England) then discussed "Automated fishscale analysis," a texture analysis and neural netapproach to identifying annuli in scales. Next upwas Dr. Valsilikov who discussed use of "spectralanalysis to count increments" and demonstrated theIM System, prototype software for imaging andautomating diagnosis of calcified structures.Christopher J. Donohoe (Oregon State University)discussed a procedure and macro he developed (andoffered to participants) for counting and measuringintervals "from core to edge at high magnification,linking measurements from sequential images. Al-

24

though scheduled to present "miscellaneous imagingsnippets in the service of otoliths and scales", PeterHagen yielded the floor for the final presentation ofthe morning to Dean Courtney (NMFS Auke BayLaboratory) who discussed juvenile "salmon scalesand otoliths Optimas macros" for increment countsand measurements. The workshop's open computersession was held conurrent with an extended lunchbreak. During the open forum after lunch, partici-pants discussion centered on a wish list for Optimas;internet communications via Optimas web and ftpsites, an e-mail listserve, and a hypernews groupestablished by Peter; tips for image enhancement,and use of marker flags. The two afternoon workshops covered useof computer image analysis for sample processing(automated or semi-automated counts and measure-ments of batches of fish eggs, larvae, or juveniles)and descriptive and taxonomic analysis (automatedor semi-automated analysis for descriptive orspecimen-identification purposes). After a briefintroduction to both workshops by Darrel Snyder,David J. Harshany (Florida Marine Research Insti-tute) discussed and demonstrated a user interface(dialog box) and set of macros he was developing toreplace the standard Optimas program menus andsemi-automate otolith marking, oocyte staging, andoocyte and general measurements by persons withlittle or no instruction. Straton Spyropoulos thensummarized various procedures in Optimas (andmany competing programs) useful for "automatedcounts and measures of batches of fish eggs, larvae,or early juveniles."

Jennifer M. Bayer (Columbia River Re-search Laboratory, Washington) opened the thirdworkshop by relating her "use of image analysis formorphometric investigation of chiselmouth andnorthern squawfish larvae." Using Jandel software,she splices anterior and posterior half images of thesubject larva together, identifies calibrated landmarkcoordinates, and from these calculates desiredlengths and other measurements. Similarly, MorganS. Busby described "a macro for collecting morpho-metric measurements of larval, juvenile, and smalladult fishes" in Optimas. The macrosemi-automates or consistently guides the userthrough the process with prompts. Based on his

work using image analysis to classify snowflakes,Edmond W. Holroyd (U.S. Bureau of ReclamationRemote Sensing and Geographic InformationGroup, Denver) discussed the probable steps in-volved of using "outline matching techniques forcomputer identification of larval and older fish." Healso described the progress he had made towardsdeveloping an algorithm for automatically measur-ing the total length of bent and curved fish larvae, aproblem that has long delayed automated batchcounts and total length measures. Finally, StratonSpyropoulos discussed "pattern recognition (andother) techniques for automated (semi-automated)specimen identification", particularly the use of ob-ject classes in Optimas. With the end of afternoonpresentations, attendance rapidly declined and rela-tively few participants remained for the combinedsecond and third workshop open forum and opencomputer sessions.

January 1998

Convened by Gordon H. Copp (Hatfield,UK) and Vladimir Kovac (Bratislava, Slovakia), the1st FONE Workshop was held at the Druzba Hotelin Bratislava (September 1primarily a self-funded workshop, a small grantgratefully received from the European Commissionmade it possible for a number of colleagues fromCentral and Eastern Europe participate in the work-shop. Originally initiated as a result of recent studiesof the early ontogeny of roach (Rutilus rutilus), theaim of the workshop was to re-evaluate metamor-phosis and the transition from larva-to-juvenile de-velopment in fishes. As such, the workshop aimed todefine better the events marking the onset of thejuvenile period. This is important for (1) the use ofontogenetic scales for inter-specific comparisons ofmorphological development, (2) the study of evolu-tionary trajectories, (3) the identification of ontoge-netic shifts in resource use, and (4) the refinement offishery recruitment models.

The 35 participants represented 14 coun-tries, including western, central and eastern Europe,as well as Japan, Canada and Australia. This varietycontributed to a vigorous debate throughout themeeting, inspired by an informal and friendly atmo-sphere. The need for an holistic approach to thestudy of fish early life history, as well as for along-awaited agreement between fish biologists andaquaculturists upon a standard terminology for in-tervals in development, were amongst the most com-pelling issues addressed by Eugene K. Balon(Guelph, Canada) in his keynote speech. All follow-ing communications and discussions, hinged on themain theme of the workshop, branched into fourmain directions: (1) ontogeny and life history traits,(2) larval and juvenile patterns of relative growth,(3) morphology, physiology, behaviour and niche,and (4) larva-juvenile shifts in resource use.

Lauri Urho (Helsinki, Finland), Dimitri A.Pavlov (Moscow, Russia), and Lorenzo Vilizi(Adelaide, Australia) collated and critically re-viewed literature data on the early ontogeny of

various freshwater and marine species, comple-mented by personal observations. These presenta-tions brought to light stark discrepancies betweenauthors as to the exact timing and succession ofearly life history intervals. These incongruities werefound to be likely due to the existence of twocontrasting schools of thought in fish early ontogenystudies: the gradualists and the saltationists. Whilegradualism holds that ontogeny occurs as a continu-ous succession of arbitrarily selected moments in development, thetheory of saltatory ontogeny purports that the spiralprogression of an organism punctu-ated by far-from-stable thresholds, separated bystabilised states in development and organised in ahierarchical sequence of intervals (periods, phasesand steps). Although experimental evidence has longfavoured saltation as the mechanism responsible forobserved changes in development, it emerged fromthe workshop that consensus among researchers isyet to be achieved. However, Gordon Copp empha-sised that the two perspectives are not mutuallyexclusive, as attributes are developed/acquired grad-ually during the intervals delineated by saltatorythresholds.

One of the highlights of the workshop wasthe oral given by Karin Pittman and Jostein Sol-bakken (Bergen, Norway) about their collaborativeresearch with fish culturists on the developmentalbiology and rearing of Atlantic halibut(Hippoglossus hippoglossus L.). All three commu-nications supported the general view that the meta-morphic process is a dramatic event, causing sub-stantial morphophysiological and behaviouralchanges. This may be the reason why some biolo-gists have proposed the term of metamorphosis, to take account of the synergisticeffect of the various factors at play during thetransition from larva to juvenile. The interestinglinks between behaviour and physiology were alsoaddressed in orals by Reiji Masuda (Argyll, UK),Jean-Marc Roussel (Rennes, France), and Yoshi-

WHEN DO FISH BECOME JUVENILES?Looking beyond metamorphosis to juvenile development

The 1st International Workshop of The Fish Ontogeny Network of Europe (FONE)

26

taka Sakakura (Guelph, Canada).Results presented by the two convenors and

a number of other participants highlighted the needfor an integrated analysis of the interactions betweenmorphology, behaviour, function and environmentfor determining when a fish has breached the larva-juvenile threshold. Following their work on the mor-phology of roach during early ontogeny, VladimirKovac and Gordon Copp presented comparativestudies on freshwater fishes that suggest that stabili-sation of allometric growth, changes in functionalmorphology and shifts in microhabitat use can beused to identify the threshold between the larva andjuvenile periods. A morphological and/or habitatapproach to identifying the larva-juvenile thresholdwas presented in poster communications by AntjeBischoff (Berlin, Germany), Rodolphe E. Gozlan(Toulouse, France/Hatfield), Laura Old (Bratislava/Hatfield), Martin Reichard (Brno, Czech Republic),Milica Stojanova (Skopje, Macedonia) and JaroslawZelepien (Olsztyn, Poland). Relative growth pat-terns during metamorphosis n some marine specieswere also examined, in oral communications by IvanKatavic (Split, Croatia) and Sergey Tsarin(Sevastopol, Ukraine).

Finally, ontogenetic shifts in microhabitatuse by young-of-the-year (0+) fish were investigatedby Etienne Baras and Joseph Nindaba (Liege, Bel-gium), Thomas Mehner (Berlin, Germany), SirkaStaff (Joensuu, Finland) and Josef Wanzenbock(Mondsee, Austria). These studies are a furtherindication of the importance to adopt an integratedapproach to the study of fish early life history, aswell as the need to evaluate the interactions betweenfish and prey populations.

On the afternoon of the Workshop's ban-quet, the convenors took the group on a field excur-sion to the Gabcikovo hydroelectric complex on theRiver Danube, which has recently been the subjectof a trial at the World Court in the Hague. It was arare opportunity for most participants to visit thiseerie and uninspired engineering achievement,whose long-term effects on the fish fauna and fresh-water habitats of the Piedmont zone of the DanubeRiver have yet to be fully evaluated. The trip wastopped off by an example of the local culturalintegration that borders the Danube, the participants

being served Hungarian purkurtt (internationallyknown as gulasz) with Czech-style dumplings,washed down with Slovak beer, wine or Kofola (thelocal type of cola).The original objective of the first FONE workshopwas to bring together of different background and experience in fish biol-ogy, with the hope to foster discussions and suggestdirections for future research. The Bratislava meet-ing no doubt has succeeded in both purposes, thanksto the enthusiastic participation of its contributorsand the unstinting efforts of the organising commit-tee. The progress made at this 1st meeting of theFish Ontogeny Network of Europe is expected to befollowed up in two years time with a 2nd workshop,tentatively to be hosted by Thomas Mehner inBerlin. Persons interested in FONE activities shouldjoin the EUROFISH eMail list, which acts as theforum for FONE exchanges of information, or alter-natively contact Gordon Copp(g.h.copp@herts.ac.uk).

Lorenzo VilizziPost-Doctoral Fellow,

Landscape & Ecology Research Group,University of Hertfordshire, UK

January 1998

UPCOMING MEETINGS

The Second International Congress onthe Biology of Fishes

The Second International Congress on the Biology of Fishes will be held July 26-30, 1998 atTowson University of Maryland, Baltimore USA. This meeting is organized by the Physiology Section ofthe American Fisheries Society and is open to all researchers, teachers, managers and students who areinterested in fish biology. Symposia to be held at the meeting include

Biology of Burbot;Culture of Fish Eggs and Larvae;

Feeding Ecology;Stress in Fish;

Smolt Physiology, Ecology and Behavior; Tropical Fish Biology and Habitat Change;

Swimming Performance;Fish Response to Toxic Environments;

Striped Bass Biology and Culture;Ammonia Excretion and Toxicity in Fish;

Fish Cardiovascular Responses to Environmental Changeand Indices of Fish Condition.

There will be a plenary session with lectures by distinguished fish biologists as well as general oralsessions and poster communications. Although there are specific symposia themes, communications andposters from all fields of experimental fish biology are quite welcome:

The venue of the meeting is the Burkshire Conference Center of Towson University, in Towson,Maryland a suburb of Baltimore. Registration packages will accomodate a variety of budgets. Suiteaccomodations are available at the Burkshire as well as at the Towson University dormitories and localhotels. Towson has convenient "light rail" access to the tourist attractions, restaurants and clubs ofdowntown Baltimore. Schedule your flights into Baltimore-Washington International Airport, if at allpossible, but there are convenient rail/shuttle links from both Washington National and Dulles Interna-tional Airports.

For more information, contactDon MacKinlay,

Dept. Fisheries and Oceans,555 West Hastings St.,

Vancouver BC,Canada V6B 5G3.

Phone: 603 666-3520,FAX: 604 666-6894,

Email: mackinlayd@dfo.mpo.gc.ca

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DATES TO REMEMBER

June 20-25, 1998 2nd International Symposium on FishOtolith Research and Application

Bergen, Norway

July 9-13, 1998 22nd Annual Larval Fish Conference Ann Arbor, MI

July 16-22, 1998 78th Annual Meeting of the American Society of Ichthyologists and Herpetolo-gists

Guelph, Ont

July 26-30, 1998 Second International Congress on theBiology of Fishes

Baltimore, MD

August 23-27, 1998 American Fisheries Society Meeting Hartford, CT

AFS-ELHSChesapeake Biological LaboratortyUniversity of Maryland Center for Environmental ScienceP. O. Box 38Solomons, MD 20688-0038

Bulk RateUS Postage PaidPermit No 45

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