Freshwater Molluscan ShellsGastropoda (Snails)

Neritinidae: Thick walled colorful shells with shelly operculum, mostly tropical, related to the marine nerites.Ampullariidae: Large "apple snails" of the tropics world wide, generally smooth.Viviparidae: "mystery snails", usually with circular or oval aperture, generally smooth.Valvatidae: Small white snails, widely umbilicate.Other freshwater snails: A few species from generally marine familiesPleuroceridae and other Cerithioidian families: Thick-walled shells, often high-spired, may have sculpture and be colored, or with color bands. North America, Africa, Asia, South America    Thiaridae: Similar to the Pleuroceridae, mainly tropical.    Melanopsidae: Similar to the Pleuroceridae; Mediterranean region, New Zealand.Rissoacea: A great many species of mostly small to tiny snails, world wide. Diverse in Australia.Freshwater pulmonate snails : Thin walled shells, world-wide, usually weakly colored, may be     dextral, (Lymnaeidae)     sinistral, (Physidae), or     planispiral (Planorbidae), or restricted to certain geographic locations such as    temperate South America (Chilinidae)    or New zealand (Latiidea)

Freshwater limpets: Thin, small, saucer or cap-shaped shells, not closely related to marine limpets.

Gastropod family tree showing relationships between the major freshwater lineages. This is a more traditional approach to classification. Recent work suggests, for instance, that the Archaeogastropoda is an artificial grouping, the Neritinidae belong in their own order and superorder, and also that the Viviparidae andAmpulariidae are separate lineages, both of which should connect at the base of the Caenogastropod branch.Furthermore, Valvatoidea do not belong with the Caenogastropoda, but with Heterostropha, an order not formerlyrecognized and not shown here. More recently, groups within the family Pleuroceridae have been raised to familystatus, so the Cerithiacea (Cerithioidea or Vermetoidea ) now contains several additional freshwater families. Click for New classification in tabulated form.

Freshwater Molluscan Shells

Neritidae (Neritinidae)

Of this family of mostly tropical shallow-water marine snails, over 175 species live in fresh or brackish waters. All graze upon algae growing on firm underwater surfaces. They are notable in having thick variably patterned shells and a calcareous operculum. Unlike most freshwater snails where young are born live or hatch directly from eggs, development in the nertiidae involves a

planktonic larval form referred to as a veliger. Tom Eichhorst indicates some species cannot reproduce in freshwater aquaria, as their veligers need exposure to saltwater to develop.

Genera of the neritidae with representatives in fresh waters include:

Neritina Indo-Pacific.Nereina Central and South America,Theodoxus; Europe, northern Africa, Middle East.Clypeolum; Central and South America, sub-Saharan Africa.Septaria; Rivers and streams of Indo-Pacific islands, Ganges and Hooghly Rivers, India.Fluvinerita; Mountain brooks of Jamaica.Neritodryas; Indo-Pacific.Neritilia; Circum-tropical.Vitta; the Americas and AfricaVittina: Indo-Pacific, southern Asia.

The ranges given above are from Banarescu, 1990, Preston, 1915, and Tom Eichhorst, who also provided images, information, and identifications. Names and classifications are currently [2004] under revision. Please note, some of the image filenames, where they contradict the captions, reflect earlier classifications, or misidentification of specimens.

Western Hemisphere

    "Olive Nerite"The name Neritina reclivata (Say,

1822)has long been used for this species,

but Vitta usnea Röding (1798) has

priority. Freshwater creeks in Florida, United States.

x2. Detail of banding to right, x8.

Clypeolum latissimus(Orbigny, 1840) Rivers,Pacific side, Equador

       

   

Clypoleum (formerly Neritina) punctulata (Lamarck, 1816).  Freshwater rivers well above marine influence, island of Dominica. Photos, Dr. Donald J. Stewart.

Vitta meleagris (Lamarck, 1822) Rio de Janiero State, Brazil

 

Vitta (formerly Neritina) virginea (Linne, 1758).West indies. Great variety of colors and patterns. Photo © Stefan Chessa / Germany.

Click here for photo collage.

Vitta zebra (Bruguiere, 1792) Near Belem, Brazil.

Europe

Some Theodoxux are noteworthy in having ranges far outside of the tropics,including England and Europe along

   

Other species listed for the territory of Europe

the Baltic Sea.

Theodoxus danubialis (Pfeiffer,1828)Italy.

Theodoxus danubialis has acquired thefollowing common names:  Czech; zubovec dunajský  German; Donau-Kahnschnecke  Hungarian; rajzos bödöncsiga.

include:  T. anatolicus Récluz, 1841, Turkey; Greece   T. baeticus Lamarck, 1822, Spain   T. euxinus Clessin, S., 1885, Europe   T. fluviatilis (Linnaeus, 1758), Europe   T. meridionalis Philippi, 1836, Italy   T. prevostianus Pfeiffer, 1828, Europe   T. tranversalis Pfeiffer, 1828, Europe   T. valentinus Graells, 1846, Spain  T. velascoi (Graells, 1846), Spain.

A few of the common names appliedto the wide-ranging T. fluviatilis:  Czech; zubovec rÃcnÃ.  English; River Nerite.  German; Gemeine Kahnschnecke,   Swedish; BÃ¥tsnäcka, Algsnäcka,   Russian; Лyнка pечнаÑ�

Africa / Asia / South Pacific

Vittina natalensis (Reeve, 1845) African rivers, in natural state and cleaned. Image; Tom Eichhorst.

 

Vittina coromandeliana (G.B. Sowerby I, 1836) left (dorsal view), and Neritodryas dubia

 

(Gmelin, 1791) right (aperture view). African rivers. Specimenscourtesy of Gerald Depaus, Belgium. ID; Tom Eichhorst.

    Clithon cf. sowerbiana (Recluz, 1841). Okinawa, Japan.

 

Clithon castanea (Hombron & Jaquinot, 1854). Samoa. Image; Tom Eichhorst.

Clithon dispar (Pease, 1867) considered tobe a subspecies of Clithon chlorostoma (Broderip, 1832) by some authors.Western Samoa.

 Vittina variegata (Lesson, 1831)New Caledonia

Clithon corona (Linnaeus, 1758) Philippines. Markings on largeindividual are concealed by algae.

Species in the fhe freshwater genus Septaria possess an internal operculum, completely buried within the foot of the animal. Tom Eichhorst indicates that it may have the function of helping to leverage the animal to the substrate, but it has never been shown for certain what if any function it serves. He provides the following information, along with the images below. The operculum in Septaria varies in size from Septaria cumingiana whose operculum is almost the same size as the snail's aperture, to Septaria tesselata in which it appears small, thin, and vestigial. Its dark corneous region fits behind the septum. At least four of the thirteen currently recognized Septaria species are sexually dimorphic; S. cumingiana (Récluz, 1842), S. porcellana (Linnaeus, 1758), S. sanguisuga (Reeve, 1856), and S. suffreni (Récluz, 1841).  These limpet or slipper-shell like nerites are typically found in fast flowing freshwater streams. Five species are listed for the Indian subcontinent by Preston, 1915.

Septaria porcellana (Linnaeus, 1758), with, and without periostracum. Philippines, actual size, 26 mm. Opercula; left, "outward" face, right, "inward" face. Photo Tom Eichhorst

 

Septaria suffreni (Récluz, 1841), Samoa. With, and without periostracum. Females, top; males, bottom. Actual size, 18 to 24 mm. Opercula; left, "outward" face, right, "inward" face. Photo Tom Eichhorst.

Freshwater Molluscan Shells / Ampullariidae

Commonly seen in aquaria, the Ampullariidae are the large apple snails of the tropics world wide. Please visit the apple snail site (http://www.applesnail.net) for extensive information on this family.

Pomacea; widespread in South America, FloridaMarisa; widespread in South AmericaAsolene; northern South America and Parana River basinFelipponea; lower Parana RiverPila; widespread in Africa, India, Southeast AsiaLanistes; widespread in AfricaSaulea; west AfricaAfropomus; west AfricaForbesopomus; Lake Lanao, Philippines

Asia

 

Pila ampullacea (Linnaeus, 1758), Bali.

  Pila polita (Deshayes, 1830), Thailand.

Africa

Pilsbry and Bequaert (1927) in their review of the African freshwater fauna include

Pila: 21 species + 2 additional subspeciesLanistes Subgenus Lanistes: 23 species + 3 additional subspeciesLanistes Subgenus Meladomus: 20 species + 9 additional subspecies and varietiesSaulea: 1 speciesAfropomus: 1 species.

Some of their illustrations are included below, courtesy American Museum of Natural History.

   Pila ovata (G. Oliver, 1804)central Africa.

  Pila wernei (Philippi, 1851)Cental Africa rivers, under water-lily pads.

  Pila leopoldvillensis (Putzeys, 1898) P. congoensis, Pilsbry and Bequaert (1927) is similar, withnarrower aperture. To 100 mm.

   Lanistes varicus Muller, 1774. Southwest Africa. Lanistes is not truly sinistral, but instead, "hyperstrophic." It might be described as a dextral shell that spirals upward as it grows, instead of downward, such that the spire has become the umbilicus, and vice-versa.

  Lanistes ovum Peters,1845,  Central African lakes.  

Lanistes bicarinatus, Germain, 1907Leopoldville, 39 mm.

 

Lanistes intortus (Lamarck 1822)30 mm, from Zambi, Malela, and Banana.

 

       Lanistes procerus langi Pilsbry and Bequaert 1927

 

 

Salea vitrea (Born, 1780)  

Afropomus balanoideus

(Gould, 1850)

 

Western Hemisphere

 

 

Asolene scalarisLamarck, Uruguay.

  Asolene megastomaneritoidea Sowerby, 1825Uruguay. Mature shell.

  Pomacea lineata(Spix, 1827), Brazil.

         

 

 

Pomacea canaliculata(Lamarck, 1819), SE.South America, common in aquariums, invasive in SE.Asia, Japan, Australia, Hawaii.

  Pomacea paludosa(Say, 1829), Florida, USA.

  Pomacea papyraceus(Spix, 1827), South America.

         

     

Pomacea insularumd'Orbigny, 1835, Uruguay.

  Felipponea neritiformisDall, 1919, Brazil.

   

 

Pomacea bridgesii (Reeve, 1856). Large mature shell. Amazon Basin. Farmed locally and eaten as "churo". Small banded individuals common in aquaria.

 

Marisa cornuarietis (Linnaeus 1758), Florida, USA, native to South America, also introduced into Africa.

Freshwater Molluscan Shells / Viviparidae

Viviparus georgianus (Lea, 1834), (left), and Campeloma limum (Anthony, 1860), (right). Campeloma has the large foot characteristic of active snails that plow through sand just beneath the surface. Both species are native to

rivers and streams of the Southeastern United States coastal plain.

Viviparidae, commonly referred to as "mystery snails" have a worldwide distribution. Burch, (1982) list 17 total species for North America. Preston, (1915) lists fourteen for India, Liu Yueyin (1979) includes twelve for China, and Zhadin, (1952) lists five for the territory of the former USSR. They are also present in Australia, Africa and Europe (six species, see Fischer), but except as fossils, absent in South America. The viviparidae are noteworthy in their wide selection of foodstuffs. Brown (1991) indicates they can function both as grazers, consuming algae growing on any submerged surface, and detritivores, utilising fine particulate organic matter and the bacteria and other microorginisms therein. They also filter feed on suspended matter, competing with the clams and mussels. Dillon (2000) indicates that North American Campeloma can also be baited with carrion, and describes the process by which Viviparus snails consume suspended particulate material.

The gills of Viviparus are characterized by unusually large triangular lamellae whose tips hang over a ciliated gutter or "food groove" running across the floor of the mantle cavity.... Cilia ...direct mucus and entrapped particles to the food groove. Particles collected on the gill filaments are carried to the tip, where they also fall into the grove. A food/mucus string forms which is carried forward and collected into a ball or "sausage". Periodically the snail will turn its head and eat the collected food.

Principal genera, in three subfamilies:

Viviparinae;    Viviparus; Eastern North America and most of Europe.    Tulatoma; endemic in Coosa River, Alabama, USA.

Campelominae or Lioplacinae;    Campeloma; Eastern North America.    Lioplax; Eastern North America.

Bellamyinae;    Bellamya; Africa, India, southeast Asia.    Cipangopaludina; east and southeast Asia, and as an exotic elsewhere.    Notopala; eastern Australia.    Larina; northeast Australia.    unclassified;     Margarya; China    Angulyagra; China    Rivularia; China    Neothauma; Africa    Heterogen; Japan    Taia; Southeast Asia

Asia

Heterogen longispira Smith, Japan.

 

Amuropaludia pachya Bourguignat,1860,

far east Russia.

  <- Cipangopaludina chinensis(Reeve, 1863), now found near Washington, DC, Southern Californialakes, and other places in the UnitedStates and Canada. The Chinesemystery snail is sold in traditionalChinese markets. Cipangopaludina japonica(Martens, 1861), also found in theUnited States, is similar, but somewhat more high-spired and angular.

 

Thick shelled Chinese Rivularia snails: Rivularia auriculata von Martens, 1875from Fujian Province, (above) and Rivularia bicarinata Kobelt, 1909 from HunanProvince. (below).

Images below from Liu Yueyin (1979)

Cipangopaludinaussuriensis (Heude), northernChina.

Margarya mansuyiDeutzenberg et Fischer, Yun Nan, China.

 

Margarya melanoidesNevill, Yun Nan regionlakes, China.

Bellamaya purificata (Heude),widespread, China.

     

probably Angulyagrapolyzonata (Frauenfeld)Canton, China

Southeast Asia

 

Filopaludina sumatrensis polygramma (Martens, 1860),Thailand

  Bellamya angularis (Muller, 1774), Philippines

 

Taia elitoralisAnnadale, 1918 (left)Anulotaia mekongensis Brandt, 1970 (center)Trochotaia trochoides (Martens, 1860) (right)

Black and white imagesfrom Brandt (1974)

Brandt (1974) lists several genera endemic to Thailand and Southeast Asia, and includes the following numbers of species for the territory of Thailand: Filopaludina 6 species plus 4 additional subspecies; Sinotaia 2; Annulotaia 2; Trochotaia 1; Eyriesia 1; Idopoma 3 Cipangopaludina1; and Mekongia 6.

 Europe

Please visit Wolfgang Fischer's page at http://ipp.boku.ac.at/private/wf/Europaeische_Viviparidae_main.html for images of the six recent and additional fossil European species.

Eng; Mystery snailsDe; SumpfdeckelschneckenIt; Viviparo, PaludinaFr; Paludine

 Ne; moerasslakenRu; Ц#150;ивоѦ#128;одки    [zhivarodki]Pol; żyworódka

Viviparus mammilatus (?) Kuster 1852, Monte Negro

Viviparus acerosus

           

Viviparus viviparus(Linnaeus, 1758) Belgium, elsewhere in

Europe

(Bourguignat 1862)Hungary

Viviparus contectus Milletponds, Hungary

Africa

Pilsbry and Bequaert, (1927) list 35 Viviparus species, with 22 additional varieties, and one species with three additional varieties for Neothauma. At least some of the Viviparus species have since been placed with Belamya. 

Neothauma tanganyicensis Bourguignat,1885. Lake Tanganyika.

Specimen contributed by Gerald Depaus, Belgium.

 

Viviparus crawshayi E. A. Smith, 1893 Zaire, Africa

 

   

Viviparus mweruensis E. A. Smith, 1893,Lake Moero, Central Africa. Shell has growth line features in common with Neothauma tanganyicensis,above, and "Neothauma differs primarily from Viviparus in th shape of the outer lip" (Pilsbry and Bequaert, 1927).

  Bellamya jeffreysiiFrauenfeld, Central Africa

  Bellamya unicolorLivier, 1806. Senegal

Australia

Larina strangei Adams 1854. Queensland, Australia.

Hugh Jones of the New South Wales Department of Land & Water Conservation  indicates that some of the Viviparidae are endangered in Australia. In particular, Notopala hanleyi and Notopala sublineata from the Murray-Darling drainage. These were thought to be extinct, but a few remnant populations have been rediscovered in irrigation pipelines. They were apparently a problem and the last known population of N. hanleyi may have been eradicated by efforts to clear the pipeline.

North America

   

Relatively high-spired Campeloma from theCache River in Arkansas.

Campeloma limum (Anthony,1860), creeks and rivers of thesouthern Atlantic coastal plain. x 2.

Campeloma decisum (Say,1817) Eastern United states andsouthern Canada generally;rivers and lakes.

Lioplax sulculosa (Menke, 1828) Americanmid south, larger rivers and reservoirs.

   

Viviparus georgianus(Lea, 1834), southeasternNorth America, apparentlyinvasivein Lake Champlain,New Your.

 Viviparus subpurpureus(Say, 1829), southeasternNorth Anerica.

 Viviparus intertextus(Say, 1829), southeasternNorth America

Viviparid opercula are concentrially structuredand assymetrical. Shown are Viviparus subpurpureus (left) and V. intertextus (right).

Freshwater Molluscan Shells

Hydrocenidae, Valvatidae, and other freshwater snails

Hydrocenidae

Minute amphibious snails classified with the old archeogastropoda, native to eastern and southern Asia, and southern Europe. One species is listed for southern Africa by Pilsbry and Becquaert (1927) "[They] are more or less amphibious dwellers in wet vegetation, clinging to the faces of rocks continually washed by the spray from waterfalls" (Preston, 1915). He lists eight species for the Indian subcontinent

Georissa japonica Pilsbry, 1900. x8. Japan

Valvatidae

Small wide-spired operculate snails, commonly refered to as valve snails, egg-laying and hermaphroditic. Burch (1982) lists 11 North American species. 11 are also listed for the former USSR by Zhadin (1952) while only two are listed for India, and one for Africa. Banarescu includes the following genera;

Valvata; (several subgenera listed by both Banarescu and Burch) throughout Europe, northern Asia, and North America.Borysthenia; Eastern and central Europe. Gagea; Endemic in Lake Ohrid.

They have a featherlike gill, visible on the left side outside the shell when the snail is active (Brown, 1991), and a ciliated pallial tentacle extending out to the right. Please see the Animal Diversity Web http://animaldiversity.ummz.umich.edu/site/accounts/information/Valvatidae.html or http://www.allesumdieschneck.de/html/valvatidae.html for pictures of living Valvata snails. Dillon (2000) says of this little studied group, that some researchers have reported filter-feeding behaviour, while others have concluded they are strictly grazers. Shell characteristics may be variable. For instance the species V. tricarinata occurs in forms having differing numbers and locations of spiral carinae or angulations. Several such forms may occur within a single population (William Heard, in Burch, 1982).

Valvata stenotrema (Polinski) Lake Ohrid, Macedonia. x8.

Valvata bicarinata Lea 1841 American midwest and northeast. x8.

Megalovalvata demersa (Lindholm, 1909) Lake Baikal. x8.

 Potamididae

A few members of this marine or brackish water family have adapted to fresh waters. Most inhabit marginally marine environments in the tropics.

 

Telescopium telescopium(Linnaeus, 1758) Brandt(1974) indicates this is a snailof "muddy irrigation trenches,drainages and swamps in themud flats." Native to much ofSoutheast Asia.

   

Cerithidea cingulata(Gmelin, 1790) Native toThailand. This image,and the photographs below are from Brandt (1974).

Buccinidae

Carniverous gastropods related to the marine whelks. Two freshwater genera, Clea and Afrocanidia.

Brandt (1974) describes and pictures six Clea (subgenus Anentome) species, but could only confirm Clea helena for the territory of Thailand. He says of Clea helena that it is the only species in Thailand that is "not restricted to running water as it is also found in lakes and ponds", and that it "feeds predominantly on decaying protein, but has been observed to attack living snails and worms."

Clea has been offered for sale in the pet trade and the possibility exists for it to become invasive. Harry Lee includes this and other information on the genus at http://www.listserv.uga.edu/cgi-bin/wa?A2=ind0712B&L=conch-l&P=R722&D=1&H=0&O=T&T=1. He also posted a listing of species at http://www.listserv.uga.edu/cgi-bin/wa?A2=ind0712B&L=conch-l&P=R1895&D =1&H=0&O=T&T=1.

   

Clea helena (Philippi, 1847) (Left) Widespread, Southeast Asia, Indonesia.Variable. x3.

Clea scalarina (Deshayes, 1876) (Right) Mekong River. Slightly magnified.

Nassariidae

Nassa mudsnails, characteristic of tidal mudflats, have also invaded fresh waters.

Banarescu (1990) mentions

Pygmaenassa - India,Nassodonta - East Asia, andArcularia - Lake Chilka, Burma.

   

Nassodonta dorri(Wattebled, 1886) Viet Nam. Photo Bill Frank, webmaster Jaxshells.org. x3.

Marginellidae

Rivomarginella morrisoni Brandt, 1968. x4Rivers, lakes, and canals along the Gulf of Thailand. One

freshwater species "Known from Thailand only" (Brandt, 1974).

Pyramidellidae

Morrisonietta siamensis Brandt, 1968. x10Prefers brackish water of low salinity. Several species endemic

to various localities in Southeast Asia (Brandt, 1974).

Freshwater Molluscan Shells / "Pleuroceridae"

Io fluvialis (Say, 1825) in habitat, northeast Tennessee, with several Leptoxis, in strong current. There have been several attempts to re-introduce this species into suitable parts of its former range, with some

success.

"Pleuroceridae": (Cerithioid snails not in families Thiaridae or Melanopsidae) Diverse in rivers of the Southeast United States. Many genera world wide. Burch in 1982 (note p. 196) discusses the various names that are applied to this family and concludes "...there is as yet no really solid basis for adequately comparing Pleurocera and its allies with Paludomus and its related taxa or Pachychilus and its relatives. Until the necessary comparative studies have been completed and evaluated, perhaps it is best to retain the family name Pleuroceridae."

Alternative classifications for the Pleuroceridae were considered by Banarescu (1990), who finally settled with the subfamilies and genera in the table below. Since that time, many genera have been reclassified, and several subfamilies have been raised to family status. Please see Bouchet and Rocroi (2009).

Pleurocerinae

Pleurocera; American interiorElimia; widespread, eastern North AmericaLithasia; Ohio River drainageLeptoxis; widespread, eastern North AmericaIo; endemic to Tennessee River and tributariesGyratoma; endemic to Coosa Riverdrainage, largely extinctJuga; American far West and Northwest.Holandriana; Danube River basinNamruta; JapanAmnipila; central MexicoPachychilus; Central and much of South AmericaDoryssa; eastern South AmericaPotadoma; central AfricaPotadomoides; southeastern AfricaPachymelania; central Africa

Lavigeriinae

Semisulcospira; East Asia and Japan

Elimia catenaria (Say, 1822) Atlantic coastal plain rivers

Lavigeria; Lake Tanganyika

Paludominae

Paludomus; India and Southeast Asia Chlorostracia; part of BurmaCleopatra; Widespread Central Africa and NilePseudocleopatra; tropical West Africaadditional genera endemic to Lake Tanganyika

Paramelaniinae = Tiphobiinae

Tiphobia; Lake Tanganyika.

According to Dillon (2000), Pleuroceridae feed on detritus or the algae growing on hard surfaces, and many seem to be able to feed on both. The family is characterized by having two sexes, male and female, but with no outward expression of gender. Reproduction is iteroparous, meaning that they may do so several times throughout their multi-year lifespans. Fertilization may occur by males releasing sperm directly into the environment, as mating behaviour has never been observed. Eggs are laid on a hard surface, for example the underside of stones, and develop into tiny snails without a larval stage.

Lithasia snails with egg masses in a tributary of the Tennessee River, laid in early spring. slightly enlarged. Photo by Mark Whited.

Syrnolopsidae, included for convenience with the African pleurocerids, but considered a seperate family.

Three genera endemic to Lake Tanganyika.

To North American Pleuroceridae

 

To African Pleuroceridae (Paludomidae, Potamididae, Syrnolopsidae)

Latin American Pleuroceridae (Pachychilidae)

Pachychilus indiorum (Morelet, 1849), Central America. This, along with P. glaphyrus, are the edible "jute snails" of the Mayas. Hundreds have been found in archaeological sites along with the clam Nephronaias ortmanni. (website) Kevin Cummings indicates these freshwater snails are fairly widespread in Central America (Mexico, Honduras, Belize, Guatemala), and Northern South America (Venezuela). There are at least 111 described taxa, many of which are recognized as synonyms.

   

Doryssa pernambucensis(Reeve, 1861), Brazil

  Doryssa cachoeirae F. Baker, 1913 Brazil  

Asian Cerithioid snails (Paludomidae and Semisulcospiridae)

 Paludomus chilinoides Reeve 1847. Sri Lanka rivers. Preston (1914) lists

64 species and a number of varieties in four subgenera: typical Paludomus, (34 species); Philopotamus (9 species) Tanalia (20 species) and Stomatodon (1 species). Most are native to Sri Lanka, with some living elsewhere in Southern and Southeast Asia. Brandt (1974) only lists one additional species for the territory of Thailand. x4

  Paludomus neritoidesReeve 1847. Sri Lanka.Approx. natural size.Large, thick shell, patternsvisible when backlit. In subgenus Tanalia. x1.

 

Paludomus loricata (Reeve). This species is sold in Europe as an aquarium snail. Listed by Preston, (1914) in the subgenus Tanalia, native to Sri Lanka "delighting in the most rapid mountain torrents." Photo by Eduardo Diaz, Spain.

 

Paludomus regalis Layard, 1854. Sri Lanka. x 1.5.

Balanocochlis glandiformis (Schepman, 1896), and operculum, Malaysia.

   

   

  Semisulcospira libertina (Gould, 1858) Taiwan

 

Semisulcospira reticulataKajiyama and Habe, Japan

  Biwamelania japonica (Smith, 1876)Lake Biwa, Japan

Freshwater Molluscan Shells

Thiaridae

The general range of the thiaridae is circum-tropical, and many of the species are extremely widespread. Their dispersal is facilitated by the fact that all are parthenogenic females. Melanoides tuberculata (Müller 1774), similar to M. maculata, below, is a common aquarium snail. Among the genera are the following;

Thiara; East Africa to Polynesia, some species also very wide ranging. Melanoides; Southern Europe, Africa Brotia; Southeast AsiaTerebia; south Asia, Oceania Sermyla; southeast Asia, Oceania Sermylasma; Australia Pseudopotamis; Australia Melanatria; Madagascar Fijidoma; Fiji Islands Tylomelania; Celebes

Cubaedomus; Cuba Aylacostoma; Central and South America Doryssa; South America (see Pleuroceridae)Hemisinus; South America

Australia

   Melanoides denisoniensis(Brot, 1877), Queensland, Australia

  Thiara balonnensis (Conrad, 1850), Queensland, Australia.

  Syrmylasma venustula (Brot, 1877),Queensland, Australia

Southeast Asia

   

Paracrostoma pseudosulcospira armata (Brandt, 1968)

  Brotia pagodula (Gould, 1847)   Brotia henriettae (Gray, 1834)

An internet search for Brotia pagodula and B. henriettae yields a number of German aquariist sites. It appears that there is a substantial trade in several Southeast Asian species to supply that market as of 2008. Shell characteristics suggest

the specimens pictured here were part of that trade, and that they may have matured in their natural environment prior to being collected and shipped off. http://www.allesumdieschneck.de/html/brotia_pagodula_english.html (accessed Sept. 2008) indicates that Brotia pagodula requires constantly moving highly oxygenated water and that most die after 6 months in an aquarium. If they are not bred in captivity it is probably best to avoid them.

   

 

Two specimens obtained from diferent sources, identified asBrotia costula (Rafinesque, 1833), (left), and Brotiacostulata (Rafinesque, 1833), (right), from Malaysia, andBangladesh, respectively. Both of these morphologies fall within the very variable subspecies Brotia (Brotia) costula costula.

 

Brotia insolita (Brot, 1868)Cambodian rivers. Brandt (1974)lists ten species and four additionalsubspecies within the genus Brotia.

Geoff Macaulay provides the following information regarding Brotia costula.

Brotia (Brotia) costula (Rafinesque, l833), is a large and widespread snail in the family Thiaridae (?) [Banarescu does not mention Brotia in his discussion of either Thiaridae or Pleuroceridae.] The best description I have is in Archiv fur Molluskenkunde 105, I-IV, 1-423, The Non Marine Aquatic Mollusca of Thailand by Rolf A. Brandt (1974). To briefly summarise this - This is an extremely variable species and also the largest Brotia. There are a great many synonyms and a wide distribution from North India, Burma, South China, continental South East Asia to Sumatra, Java and Borneo. It occupies many different habitats. Brandt recognises 3 races: Brotia costula costula (Rafinesque 1833), B. c varicosa (Troschel 1837) and B. c peninsularis Brandt l974. Synonyms for costula costula include variabilis Benson, herculea Gould, indica Souleyet, corrugata Reeve, jullieni Deshayes, and peguensis Morelet.

Also see Köhler and Glaubrecht's 2006 paper on the systematics of Brotia, placing the genus in the family Pachychilidae: http://download.naturkundemuseum-berlin.de/frank.koehler/Brotia_2006.pdf

Indo-Pacific

 

 

Thiara winteri Von Dem Busch, 1842,Philippines, x2

  Thiara, unknown sp.,Philippines, x2.   Thiara, unknown sp., Philippines. Small

shell, x4.

Adult, front and back, and immature individuals, more magnified. Unknown Thiara species,probably T. amarula, T. terpischore, or T. macrospira. Photos and ID's provided by Don Barclay.

 

Melanoides torulosa (Bruguiere, 1789) Philippines

Unknown species, Philippines    

 Unknown Melanoides sp.Philippines

  Melanoides maculata(Bruguiere, 1789), Philippines.

 

Melanoides granifera, (Lamarck, 1822) Philippines.  

Thiara cancellata, (Roeding, 1798)cleaned with bleach, from

the Philippines. Projections are shelly.

Another presumptive Thiara cancellata(?) Java rivers. The thin projections are periostracal (soft organic)

material.  

South America

 

 

Hemisinus eduardsi(Lea, 1852), Brazil, slightly enlarged.

  Aylacostoma pulcher(Reeve, 1860), Brazil,slightly enlarged.

 Aylacostoma francana (Ihering, 1909). Sao Paulo State, Brazil. x3.

Africa

Pilsbry and Bequaert (1927) list 23 species and 8 additional subspecies of Melanoides for the African continent outside Lake Nyassa. They include an additional list of 38 species (in several dubious genera) for that lake compiled from Bourguignat, but add "We do not care to add new name combinations for a host of merely mutational forms" They felt the task of determining the actual number of species in Lake Nyassa, taking into account variation typical within species, was outside the scope of their work. Below is a small sample of those figured from the rest of the continent.

 

Left to right:Melanoides anomala (Dautzenberg and Germain, 1914) 8 mmM.liebrechtsi (Dautzenberg, 1901) 24 mm.M. bavayi (Dautzenberg and Germain, 1919) ? mmM. nsendweensis consobrina (Dupuis and Putzeys 1900) 13.5 m

 

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Freshwater Molluscan Shells

Thiaridae

The general range of the thiaridae is circum-tropical, and many of the species are extremely widespread. Their dispersal is facilitated by the fact that all are parthenogenic females. Melanoides tuberculata (Müller 1774), similar to M. maculata, below, is a common aquarium snail. Among the genera are the following;

Thiara; East Africa to Polynesia, some species also very wide ranging. Melanoides; Southern Europe, Africa Brotia; Southeast AsiaTerebia; south Asia, Oceania Sermyla; southeast Asia, Oceania Sermylasma; Australia Pseudopotamis; Australia Melanatria; Madagascar Fijidoma; Fiji Islands Tylomelania; Celebes

Cubaedomus; Cuba Aylacostoma; Central and South America Doryssa; South America (see Pleuroceridae)Hemisinus; South America

Australia

   Melanoides   Thiara balonnensis (Conrad,   Syrmylasma venustula (Brot, 1877),

Queensland, Australia

denisoniensis(Brot, 1877), Queensland, Australia

1850), Queensland, Australia.

Southeast Asia

   

Paracrostoma pseudosulcospira armata (Brandt, 1968)

  Brotia pagodula (Gould, 1847)   Brotia henriettae (Gray, 1834)

An internet search for Brotia pagodula and B. henriettae yields a number of German aquariist sites. It appears that there is a substantial trade in several Southeast Asian species to supply that market as of 2008. Shell characteristics suggest the specimens pictured here were part of that trade, and that they may have matured in their natural environment prior to being collected and shipped off. http://www.allesumdieschneck.de/html/brotia_pagodula_english.html (accessed Sept. 2008) indicates that Brotia pagodula requires constantly moving highly oxygenated water and that most die after 6 months in an aquarium. If they are not bred in captivity it is probably best to avoid them.

     

Two specimens obtained from diferent sources, identified asBrotia costula (Rafinesque, 1833), (left), and Brotiacostulata (Rafinesque, 1833), (right), from Malaysia, andBangladesh, respectively. Both of these morphologies fall within the very variable subspecies Brotia (Brotia) costula costula.

 

Brotia insolita (Brot, 1868)Cambodian rivers. Brandt (1974)lists ten species and four additionalsubspecies within the genus Brotia.

Geoff Macaulay provides the following information regarding Brotia costula.

Brotia (Brotia) costula (Rafinesque, l833), is a large and widespread snail in the family Thiaridae (?) [Banarescu does not mention Brotia in his discussion of either Thiaridae or Pleuroceridae.] The best description I have is in Archiv fur Molluskenkunde 105, I-IV, 1-423, The Non Marine Aquatic Mollusca of Thailand by Rolf A. Brandt (1974). To briefly summarise this - This is an extremely variable species and also the largest Brotia. There are a great many synonyms and a wide distribution from North India, Burma, South China, continental South East Asia to Sumatra, Java and Borneo. It occupies many different habitats. Brandt recognises 3 races: Brotia costula costula (Rafinesque 1833), B. c varicosa (Troschel 1837) and B. c peninsularis Brandt l974. Synonyms for costula costula include variabilis Benson, herculea Gould, indica Souleyet, corrugata Reeve, jullieni Deshayes, and peguensis Morelet.

Also see Köhler and Glaubrecht's 2006 paper on the systematics of Brotia, placing the genus in the family Pachychilidae: http://download.naturkundemuseum-berlin.de/frank.koehler/Brotia_2006.pdf

Indo-Pacific

 

 

Thiara winteri Von Dem Busch, 1842,Philippines, x2

  Thiara, unknown sp.,Philippines, x2.

  Thiara, unknown sp., Philippines. Smallshell, x4.

Adult, front and back, and immature individuals, more magnified. Unknown Thiara species,probably T. amarula, T. terpischore, or T. macrospira. Photos and ID's provided by Don Barclay.

 

Melanoides torulosa (Bruguiere, 1789) Philippines

Unknown species, Philippines    

 Unknown Melanoides sp.Philippines

  Melanoides maculata(Bruguiere, 1789), Philippines.

Melanoides granifera, (Lamarck, 1822) Philippines.  

Thiara cancellata, (Roeding, 1798)cleaned with bleach, from

the Philippines. Projections are shelly.

Another presumptive Thiara cancellata(?) Java

rivers. The thin projections are periostracal (soft organic)material.  

South America

 

 

Hemisinus eduardsi(Lea, 1852), Brazil, slightly enlarged.

  Aylacostoma pulcher(Reeve, 1860), Brazil,slightly enlarged.

 Aylacostoma francana (Ihering, 1909). Sao Paulo State, Brazil. x3.

Africa

Pilsbry and Bequaert (1927) list 23 species and 8 additional subspecies of Melanoides for the African continent outside Lake Nyassa. They include an additional list of 38 species (in several dubious genera) for that lake compiled from Bourguignat, but add "We do not care to add new name combinations for a host of merely mutational forms" They felt the task of determining the actual number of species in Lake Nyassa, taking into account variation typical within species, was outside the scope of their work. Below is a small sample of those figured from the rest of the continent.

 

Left to right:Melanoides anomala (Dautzenberg and Germain, 1914) 8 mmM.liebrechtsi (Dautzenberg, 1901) 24 mm.M. bavayi (Dautzenberg and Germain, 1919) ? mmM. nsendweensis consobrina (Dupuis and Putzeys 1900) 13.5 m

Freshwater Molluscan Shells

Melanopsidae

The Melanopsidae have a strange disjunct distribution, mostly around the Mediterranean.

Melanopsis is native to Spain, Morocco, and the Middle East,Esperiana is found in Central Europe, but their closest relative,

Zemelanopsis, is native to New Zealand and New Caledonia.

Faunus (placed in the family Thiaridae by many authors, and Potamididae by Brandt (1974)) ranges through Southeast Asia, the East Indies, and Madagasgar.

According to Behrendt, the Melanopsidae can feed on detritus or the algae growing on hard surfaces, and many are willing to consume either. Sexes are separarate, and adult females have a small whitish reproductive opening on the right side of the foot. Reproduction occurs several times throughout the multi-year life of the snail. Fertilization may occur by males releasing sperm directly into the environment, as mating behaviour has not been observed. Eggs are usually layed in clutches on hard surfaces such as the underside of stones, but may also be scattered on soft substrates, and hatch into tiny snails without going through a larval stage.

Northern Africa

 

Melanopsis attenuata (Pallary, 1920), Morocco, from two different sources. The magnified specimen (left) shows no trace of the color banding seen in the specimens above.  

Melanopsis cesari Pallary, 1920.Morocco. x3.

 

 Melanopsis buccinoidea Olivier, Jordan River

  Melanopsis foleyi (Pallary),Morocco

    Melanopsis magnifica Bourguignat,

with periostracum removed, Morocco.  Melanopsis magnifica ingens Pallary, Morocco.

 

These specimens were obtained from dealers identified as "Melanopsis praemorsa (Linnaeus, 1758)", the left pair from Crete, Greece, and the right from the Sea of Galilee. Van Damme (1984) also includes within this named species all of the forms from northern Africa, some of which are shown above. This may have been in response to the earlier excesses of Jules Rene Bourguignat, "one of the epigons of Victorian species-makers," Van Damme expressed the opinion that his species splitting, ignoring natural variation, caused permanent damage to African malacology. He goes on to mention that Pallary was "a staunch devotee of Bourguignat."

Europe

 

 

Esperiana esperi (A. Ferrusac, 1823), Danube River, Hungary.

  Esperiana daudebartii acicularis (Prevost 1821),

  Unknown Melanopsis spHot spring in Zaragosa, Spain.

Romania

 

Melanopsis bicarinata Spain

Indo-Pacific Faunus species

 Faunus ater (Born, 1778), native to Philippines, Southeast Asia, and the East Indies. Brandt (1974) includes Faunus with the family Potamididae and indicatesthat "It lives in fresh as well as slightly brackish water near the coast in creeks, small rivers and lagoons."

  unknown Faunus species,Madagascar.

New Zealand and Oceania

 

Zemelanopsis trifasciata Gray, 1843,North Island of New Zealand, streams.   Melanopsis frustulum

Morelet, 1856. New Caledonia

Freshwater Molluscan Shells

Hydrobiidae (Somatogyrus), unknown species, from the Chunkey River, Mississippi, United States. Collected September 2000.

Hydrobiidae and Allied Families (Superfamily Rissoacea, Hydrobioidea, or Truncatelloidea)World wide, these are the small ones, ranging down almost to the microscopic. Magnifications used here are approximately 4 x and 8 x, for filenames ending with 300 and 600 respectively (see scales). In the author's experience in the south-central United States, such "microshells" are generally uncommon, only occasionally found in flood-deposited creek drift. In some instances they can be abundant, as in widely scattered springs, or at one locality in coastal Georgia where a few seeps flow around cement sidewalks, and another, a reach of the Chunkey River in Mississippi, where they swarmed over bedrock, filamentous algae, and sand. Thompson, in http://www. flmnh. ufl.edu/natsci/malacology/fl- snail/snails1.htm indicates that many species are annual, with a single brood, and a complete turnover of individuals every year. He also points out that there is a great deal more variation between various taxa than would be suggested by the often similar shells.

Classification:The classification of this enormous group of organisms is under review. Banarescu provides the following information:

Pomatiopsidae: Two subfamilies Pomatiopsinae, and Triculinae. Pomatiopsinae contains genera Erhaia, China; Aquidauania, central South America; Tomichia, South African rivers; Coxiella and Coxielladda from west and south Australia; Oncomelania, from east Asia; Blanfordia, and Fukuia, Japan; Cecina, Japan, Manchuria, and western North America; and Pomatiopsis, North America. The Triculinae include twelve genera, all in south and southeast Asia. Nine are endemic to the Mekong River.

Bithyniidae: Gabbiella, central Africa; Jubaia, and Incertihydrobia, east Africa; Sierraia, west Africa; Funduella, Limnitesta, and Congodoma, south-central Africa; Gabbia, central Australia; Emmericiopsis, Mysorella, Parabithynia, Pseudovivipara, and Sataria, endemic in various locations, south, and southeast Asia; Hydrobioides, south Asia; Petroglyphus, Phillipines; Allocinma, widespread in southern Asia; Bithynia, Europe through central Asia, introduced (possibly native) to North America.

Baicaliidae: Baicalia, endemic to Lake Baical.

Benedictiidae: Kobeltocochlea, Lake Baical and Lake Hubsugul (Mongolia); Benedictia, Lake Baical.

Pyrgulidae: Several genera in southern Europe and Turkey, one, Antroselates, in Indiana and Kentucky caves. Burch, 1982 includes this later with family Micromelaniidae.

Hydrobiidae: A very large family with hundreds of genera. These can be grouped into a number of subdivisions, many of which are considered distinct families or subfamilies by various authors. Banarescu discusses some of the disagreements in classification schemes, and offers the following informal groupings, or "lineages":

Lithoglyphine, eastern and far western North America, southern Europe. Glacidorbis, Tasmania, south Australia, and Chile.*Orientaliine - horatiine - amnicoline, eastern and north-central North America; many genera, subfamilies in southern and central Europe, Turkey.Fontigentine, eastern North America.Nymphophiline; most of area of United States.Cochliopinine; Central America, Antilles, Peru.Littoridinine; Mexico, Central and northern South America.Mexithaumine; Rio Grande, Equador.Emmericiine; western Balkan Peninsula.Lithoglyphuline; western Balkan Peninsula, Danube basin.Bythinelline; Europe, largely on southern peninsulas. Moitessierine; Europe, largely on southern peninsulas. Fluvipupa; Australia, New Guinea, Tasmania, New Zealand.

* Ponder (1986) assigns the genus Glacidorbis to its own family and superfamily within the pulmonate Basommatophora!

A commonly used classification scheme for the hydrobiidae is based on anatomical structures of the male reproductive organ or "verge" (Burch,1982), although there is question as to whether the resulting system is correct. He includes three families, five subfamilies, 29 genera, four additional subgenera, and 158 species for North America in his superfamily Truncatelloidea. He places the family Bithyniidae, with its one probable introduced species in North America, in the superfamily Ampullarioidea, (Viviparoidea) however, with the much larger Viviparidae and Ampullariidae.

Truncatelloidea

Micromellaniidae: Antroselates spiralis alone in North America is included in this family. Based on radular characteristics, it includes species from Lake Baikal, and other large lakes in southeastern Europe and Asia.

Hydrobiidae:

Hydrobiinae: Aphastracon, Hoyia, hyalopyrgus, Littoridinops, Probythinella, Pyrgophorus, Tryonia.Lithoglyphinae: Antrobia, clappia, Cochliopina, Fluminicola, Gillia, Lepyrium, Somatogyrus (Somatogyrus

s.s., and Walkerilla).Nymphophalinae: Birgella, Cincinnattia, Fonticella (Fonticella s.s., Microamnicola, and Natricola), Marstonia, Notogilla, Orygoceras (name under review), Pyrgulopsis, Rhapinema, Spilochlamys, Stiobia..Amnicolinae: Amnicola (Amnicola s.s., and Lyogyrus), Hauffenia, Horatia.Fontigentinae: Fontigens.incertae sedis: three species.

Pomatiiopsidae Pomatiopsis.

North America

 

   

Pomatiopsis lapidaria (Say, 1817) south central United States. (Pomatiopsidae)

  Fluminicola nuttalliana (Lea, 1838)Columbia River basin, Pacific northwest.(Hydrobiidae) Up to 10 mm, relatively largefor the family, it inhabits most creeks and small rivers. Operculum, inner side, upperleft.

   

 

   

  Probable Marstonia species, from spring inupper East Tennessee, February, 2002. Of anumber of specimens examined, none displayed

 

the verge, suggesting parthenogenicity in thepopulation.

 

Europe

   Chilopergula prespensis(Urbansky) Macedonia.(Micromelaniidae)

  Emmercia patula (Brumati, 1838)Croatia. (Micromelaniidae)

  Bithynia leachi Italy.(Bithyniidae)

 

 Lithoglyphus naticoides (Pfeiffer)Hungary. (Hydrobiidae)   Potamopyrgus jenkensi E. A. Smith

Hungary. (Hydrobiidae)

Asia

 

 

Bythnia kiusiuensis (Hirase, 1957)Japan. (Bithyniidae)

  Gabbia longicornis (Benson)Viet Nam. (Bithyniidae)  

Bithynia tentaculata (L., 1758)Europe, Asia, and North America(introduced). (Bithyniidae)

         

 

 

Stenothyra basiangulata Mori,1838 Japan. (Stenothyridae) Brandt(1974) includes 16 freshwater and 15 brackish water species for the territoryof Thailand in Stenothyra.

  Caspiohydrobia issykkulensis(Clessin, 1894) Kyrgystan.(Hydrobiidae)  

Paludinella devilis(Gould, 1861) Japan.(Hydrobiidae)

         

 

 

Hydrobioides striatulus(Benson) Viet Nam. (Hydrobiidae)

  Blanfordia japonica(A. Adams, 1854)Japan. (Pomatiopsidae)

 Fluvicingula elegantula(A. Adams, 1861), Japan.(Iravadiidae)

 

Mekong River Pomatiopsidae:

             Paraprosthenialevayi (Bavay,1895) x8

    Lacunopsis harmandiPoirier, 1881. x4

      Pachyhydrobiaspinosa Poirier,1881 x4 Notesingle spine on back of shell.

    Jullienia harmandiPoirier, 1881.x4

to Australian region

South America

 Litoridina australis(d'Orbigny, 1835),

  Potamolithus jacuyensis Pilsbry,1899 Brazil. (Hydrobiidae)

Uruguay. (Hydrobiidae)

Freshwater Molluscan Shells / Pulmonata / Basommatophora

Physella sp.

Freshwater Pulmonate GastropodsFreshwater pulmonate snails are characteristically thin and light shelled. Many can regulate their buoyancy to neutral and even positive by taking air into a "lung," which allows them to glide upside down on the air/water surface. Their life cycle is rapid. In nature, one or two generations per year may be produced, with complete replacement of individuals (Brown, 1991). All are hermaphroditic; that is, each individual has the capacity to function as both male and female. Unlike the prosobranchs, with many endemic species and varieties, the pulmonate species are fewer but much more widespread. Freshwater pulmonates reach their greatest size and diversity in the northern latitudes, and many species are commonly found in shifting and ephemeral habitats.

Although all are in the subclass Pulmonata, the freshwater pulmonate snails are not closely related to the land snails. Terrestrial pulmonates ("true" land snails) are in the Order Stylommatophora, while the freshwater pulmonates, considered as the single superfamily Lymnaeacea by some authors, are placed in the Order Basommatophora, along with the marine pulmonate "false limpets," superfamily Siphonariaceae. Freshwater limpets are also Lymnaeacean, but their limpet-like form has evolved several times within this group, from different coiled ancestors. The marine superfamily Melampoidea (Ellobioidea) are included as a third grouping within Basommatophora by some authors, but are given a separate order, Archaeopulmonata, in more recent sources.

Abbott (1989) uses:

Order Archeopulmonata, with a single superfamily,

Ellobioidea (littoral marine "melampus" shells)

Order Basommatophora, with seven superfamilies:

Amphiboloidea (marine)Chilinoidea

Chilinidae (South American freshwater snails)Latiidae (New Zealand freshwater limpets)

Siphonarioidea (marine "false limpets")Acroloxoidea (freshwater limpets [in part])Lymnoidea (dextral* pond snails, limpets)Physoidea (sinistral* pond snails)Planorboidea (ramshorn pond snails, limpets).

Banarescu (1990) for freshwater taxa only, uses:

Order Basommatophora with a single freshwater superfamily;

Lymnaeacea, containing six families in two sublineages:

Chilinidae (South American freshwater snails)Latiidae (New Zealand freshwater limpets)Acroloxidae (freshwater limpets [in part]), and

Lymnaeidae (dextral* pond snails, some freshwater limpets)Physidae (sinistral pond snails)*Planorbidae (ramshorn pond snails, other freshwater limpets)

* Sinistral and dextral refer to the mapping of rotation direction to a straight line vector. Most snail shells, as well as common screws, etc., are dextral, or right-handed. Take your right hand. Point the thumb in the general direction the screw moves as it rotates or the shell grows as it spirals downwards (down), and your curled fingers will define the direction of rotation for right-handed shells, screws, etc. Likewise for sinistral or left-handed snail shells, but in reverse.

Freshwater Molluscan Shells: Pulmonata

families [Physidae] [Lymnaeidae] [Chilinidae] [Planorbidae]

LymnaeidaeThe Lymnaeidae are cosmopolitan, with members on all continents and large islands, and even some smaller oceanic islands. Most, in the subfamily Lymnaeinae, are dextral pond snails, while those in the subfamily Lancinae are limpet-like. Burch lists 57 species in nine genera for North America. In common with other freshwater pulmonates, all feed on algae and detritus, and all are hermaphroditic. Species are fewer and smaller in the tropics, where they may carry parasites including trematodes and flukes.

Burch, (1982) uses the following classification for North American Lymnaeids:

Family Lymnaeidae

Subfamily Lymnaeinae

Genus AcellaGenus BulimneaGenus Fossaria, with subgenera Fossaria ss., and BakerilymnaeaGenus LymnaeaGenus PseudosuccineaGenus RadixGenus Stagnicola, with subgenera Stagnicola ss., and Hinkleyia

Subfamily Lancinae (all limpet-like; see Freshwater limpets)

Genus FisherolaGenus Lanx, with subgenera Lanx ss, and Walkerola

Bulimnea megasoma (Say, 1824) North-central United States and adjacent Canada, shallow water, smaller lakes.

 

These two species are commonly foundcrawling on mud and debris, just above the waterline of ponds or slow-moving creeks.

Fossaria obrussa Say, 1825. Southeastern United States.

  Pseudosuccinea columela (Say, 1817) Eastern North America

Stagnicola elodes(Say, 1821) Much of the U. S. and Canada.

Stagnicola caperata (Say,1829) Northern North America.

Stagnicola montanensis(Baker, 1913) Rocky Mountains.

Stagnicola emarginata (Say, 1832)Eastern Canada and Northeast U.S.

Lymnaea peregra (Muller, 1774)Europe. Halstead's Golden Guide to Tropical Fish indicates this species should be avoided in aquaria becauseit produces a poison fatal to fish.

Lymnaea stagnalis (Linne, 1758) Europe, also North America.  

Lymnaea (Stagnicola) fuscus (C. Pfeiffer, 1821) from Bulgaria (left) and Lymnaea palustris (Muller, 1774), from Kazakhstan (right).

 

Lymnaea luteola australis Annandale & Rao, 1925. Sri Lanka. x3.

 

Identifications provided by Richard Ottermans. Both x2.

 

Pseudosuccinea peregrina (Clessin,

1822) Farm ponds,southern Brazil  

Austropeplea lessoni (Deshayes, 1830) New South Wales,

Australia.

     

Lymnaea (Radix) natalensis Krauss, 1848South Africa. Image from Pilsbry and Bequaert, 1927,

courtesy American Museum of Natural History

Freshwater Molluscan Shells: Pulmonata / Physidae

families [Lymnaeidae], [Planorbidae], [Chilinidae]

The Physidae, sinistral pond snails, are commonly referred to as tadpole snails or pouch snails. They are widespread, abundant, and tolerant of pollution. Burch (1982) indicates that they are most abundant in the New World. They have evidently found a shell morphology suitable for their life station, as he goes on to say "...the physids have undergone considerable diversification,

much of which is not clearly exhibited in their shells. Many of the species [and genera] are not easy to identify on shell characters alone."

They have been used in studies of ecophenotypic plasticity, a so-called phenoplastic switch. Burt Vaughan of Washington State University indicates several studies in M. J. West-Eberhardt's recent compendium of research, "Developmental Plasticity & Evolution"  (Oxford Press, 2003, pp. 307-362). A typical example involved rearing Physa gyrina, or P. heterostropha in controlled pair groups in either water in which crayfish co-existed or water in which only fish co-existed. Within a month, differences in shell morphology appeared; i.e., snails exposed to shell-crushing fish predators showed wide apertures and very much strengthened, rotund shells. Snails exposed to crayfish only showed narrow-apertured, thin elongate shells, with barricading teeth.

Banarescu lists the following classification for the Physidae:

Family Physidae (with number of taxa listed by Burch (1982) for North America:)

Subfamily Physinae

Genus Physa most of Northern Hemisphere. (2 sp. plus 1 additional morph)Genus Physella, Holarctic,containing subgenera;Physella s.s. (16 species, 15 subspecies, and several additional morphs), subgenus Costatella, (14 species with 13 additional subspecies and morphs, and subgenus Petrophysa (1 species).

Subfamily Aplexinae

Genus Aplexa most of Northern Hemisphere. (1 species plus 1 morph)Genus Stenophysa Central America Mexico, introduced in Texas. (2 species)

 

 

Physella species, probably Physella gyrinaaurea (Lea, 1838). East and central UniteStates. Many subspecies and morphs of Physellagyrina have been named.

 Physella heterostropha halei(Lea, 1864) Central and SouthernUnited States, ponds.  

Unidentified Physella species,small western Montana creek.

   Aplexa hypnorum, Moscow, Russia   Physa albertisi Clessin,

1866. Papua New Guinea  Physa cubensis

Brazil

 

Freshwater Molluscan Shells: Pulmonata

families [Physidae], [Lymnaeidae], [Chilinidae]

Family Planorbidae

Generally referred to as "Wheel Snails", "Orb Snails", or "Ramshorn snails", the Planorbidae are the largest family of aquatic pulmonate gastropods, with species present on all continents and most islands. They are sinistral in their orientation, in spite of the fact that some may appear dextral due to the spire being sunken more than the umbilicus. Many of these species harbor the larvae of parasitic worms, particularly southern and Old-World taxa. Some are patelliform or limpet-like (see Freshwater limpets). Banarescu (1990) provides the following classification, here tabulated. Many subgeneric and subspecific names are in use, so for instance, the first specimens pictured are Planorbella (Pierosoma) trivolvis trivolvis (Say, 1817).

  Subfamily Tribe Genus

  Rhodacmeinae   Rhodacmea; Southeast North America. Limpet-like.

   Bulinini

Bulinus; Africa, West Asia, southern EuropeIndoplanorbis; Southern AsiaLaevapex; eastern North America, limpet-like.Gundlachia; South and Central America

  Bulininae Physastrini

Isidorella; south and west AustraliaBayardella; localities in AustraliaPatelloplanorbis; New Guinea, Limpet-like?Oppletora; northern AustraliaAncylastrum; Tasmania Limpet-like?Miratesta; Celebes Is.Protancylus; Celebes Is. Limpet-like?Pettancylus; Southeast Asia, Australia, and the Pacific, East Africa. Limpet-like?Barnupia; north Australia and New Guinea, East Africa, Limpet-likeFerrisia; temperate North America. Limpet-likeGlyptophysa; southern Australia, New ZealandPhysastra; Australia and New Zealand, New GuineaAmeriana; North and northeast Australia

   Camproceratini Helisoma North America

Planorbarius SiberiaCamptoceras east and Southeast Asia

    PlanorbuliniPlanorbula, (including Menetus, Promenetus, and Planorbellaof Burch, (1982); all North American.

    Biomphalarinii Biomphalaria; central Africa and Central and South AmericaDrepanotrema; South America, Antilles

 

Planorbinae

Planorbini

Planorbis; Europe, western Asia, northern AfricaAfrogyrus and Afrogyrorbis; East Africa and MadagascarAnisus; Europe and West Asia.Bathyomphalus; Europe and much of SiberiaChoanomphalus; Lake BaikalGyraulis; all of both Europe and Africa, except Sahara

    Segmentini

Segmentina; most of Europe and SiberiaHippeutis; most of Europe through central SiberiaLentorbis and Segmentorbis; Central and Southern AfricaPolypylis; coastal eastern asia and JapanHelicorbis; East and Southeast Asia

    Ancylini Ancylus; Northern Hemisphere, discontinuous, Limpet-like

  Uncertain   Neoplanorbis and Amphigyra; southeastern North America

 

Planorbella trivolvis (Say, 1817) Eastern and Central Canada and Northern U.S. Four views of two specimens:1) Apertural view with left side to left. 2) Left or spire side of shell. 3&4) Right, or umbilical side     

Planorbella scalaris(Jay, 1839) Florida

Helisoma anceps(Menke, 1830)Eastern, central, andnorthern North America.

Planorbella campanula(Say, 1821)North-Central North America

 

 Planorbella tenuis (Dunker, 1850)Southern United States, Mexico; ponds.

  Biomphalaria havanensis (?) (Pfeiffer, 1839) Southern U. S., Central America, West Indies; ponds.

 

 Snail shell obtained from a breeder in Belgium, courtesy ofGerald Depaus. Possibly Planorbella occidentalis(Cooper, 1870) or Planorbella ammon (Gould, 1855)

 

Drepanotrema lucidum (Pfeiffer)West Indies

Anisus filiaris (Gredler, 1885)western Asia

   

Anisus vortex Europe Bathyomphalis contortus(Linne, 1758) Europe

   Hippeutis umbilicalis (Benson, 1836) x4 (left)

Gyraulis siamensis (Martens, 1867) x4 (right) Brandt (1974) lists six Gyraulis, one

Hippeutis and three Segmentina species for the territory of Thailand, some of which are hosts to Echinostoma and other parasites. All are small inconspicuous snails.Images from Brandt (1974).

 

Anisus leucostoma(Millet, 1813).

Hungary. x 6

 

 

Planorbis corneus (L., 1758) Europe   Planorbid species from a pond in thesouth-Central United States, possibly anaquarium escapee.

Indoplanorbis exustus (Deshayes, 1834). Sri Lanka. x3

 

Biomphilaria tenagophila tenagophila(Orbigny, 1835). Bahia

State, Brazil. x 3.

 

Isidorella hainesii (Tryon, 1866) Victoria, Australia.   Isidorella newcombi (Adams & Angas, 1864)South Australia.

Glyptophysa gibbosa (Gould, 1546)Queensland, Australia.

 Bulinus senegalensis O. F. Müller, 1781Africa. Largest specimen is 4.4 mm. Despite the resemblance of these shells to the Physidae, theyhave been included with the Planorbidae in allsources available. The name Bulinus was originally applied by Müller to include Physa snails, and controversy has existed as to whether "Bulinus" might havepriority for Physa. (Pilsbry and Becquaert, 1927)

 

Physopsis africanaglobosa (Morelet, 1866). Africa, to20 mm. long.

Black and whiteimages from Pilsbryand Becquaert,1927, courtesy of the American Museum of NaturalHistory

Freshwater Molluscan Shells

Chilinidae native only to the temperate southern regions of South America, one genus,

Chilina, with 23 species listed by Pilsbry (1911) for the area east of the Andes.

Pilsbry goes on to indicate

"Chilina occupies the temperate and cold zones of South America from the Tropic of Capricorn to Cape Horn [and the Falkland Islands] ...Within their area, the Chilinidae are abundant snails in all suitable stations... They swarm in springs, small streams, lakes, and in some places the margins of rivers. They are most abundant southward, becoming rarer and local toward the northern borders of their range. The species from west of the Andes are in all cases, so far as we know, distinct from those east ot the divide....The eastern fauna ... inhabits a comparitively arid region, poorly watered by roughly parallel streams flowing southeastward into the Atlantic. Each of the principal river systems has its own series of freshwater mollusks, in large part distinct specifically or racially from those of other rivers."

Brace, (1983) indicates that they are adapted through both physical and behaviorial features to burrowing in soft substrates . He also suggests that morphological evidence supports the relationship of Chilina, and by inferance, the rest of the Basommatophorans, to primitive opistobranch gastropods.

Chilina fluminea Orbigny, Buenos Aires Province, Argentina

 

   Chilina dombeiana (Bruiguiere, 1789), Rio Negro province, Argentina

  Chilina globosa Sowerby

1841. Buenos Aires Province,

Argentina. x3.

  Chilina neuquenensisMarshall, 1933 Rio Negro province, Argentina

[Lymnaeidae], [Planorbidae], [Chilinidae] [Physidae]

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Freshwater Molluscan Shells: Limpets

families [Physidae] [Lymnaeidae] [Chilinidae] [Planorbidae]

Freshwater limpets are small to minute and, like freshwater mollusks in general, polyphyletic. None are related to marine limpets. In freshwater mollusks, a limpet-like form has arisen multiple times from more than one lineage of coiled aquatic pulmonate snails, but from pulmonates alone. Somewhat similar forms from the family Latiidae (also pulmonate) and the non-related Neritidae lack the centralized apex. The Lancinae are confined to the Pacific

drainages of North America while the Acroloxidae have an extremely disjunct distribution, several widely separated localities scattered over the northern hemisphere. They share a dextral organization of soft anatomy which is reflected in the assymetry of their shells. "Ancylidae" (taxomomic groups within the Planorbidae) have a sinistral organization, and a corresponding sinistral assymetry in the shell, and a near worldwide distribution.

Burch, (1982) uses the following classification for North American freshwater limpets:

Order Superfamily Family Subfamily Genus

  Acroloxoidea Acroloxidae   Acroloxus

Limnophila Lymnaeoidea Lymnaeidae LancinaeFisherolaLanx, with subgenera Lanx ss, and Walkerola

 Ancyloidea(superfamily alsoincludes familiesPhysidae, Planorbidae)

Ancylidae

Ancylinae

Ferrissinae

Laevapecinae

Rhodacmaea

Ferrissia

HebetancylusLaevapex

Banarescu's more conservative approach uses:

Superfamily Family Subfamily Tribe genus

  Acroloxidae     AcroloxusPseudancylastrum

  Lymnaeidae Lancinae  FisherolaLanx, with subgenera Lanx ss, and Walkerola

Lymnaeacea   Planorbinae Ancylini Ancylus

  Planorbidae Bulininae

Physastrini

Bulinini

FerrissiaPettancylusPatelloplanorbisAncylastrum

Laevapex

    Rhodacmeinae   Rhodacmaea

 

A few examples, all magnified:

Lanx subrotundata (Tryon, 1856) At 10 mm, relatively large for a freshwater limpet. Living animal, (8x) and shells, 4x. From a river in Oregon flowing over bedrock. When in habitat, each animal has a small tuft of algae fibers on the shell, though none was growing on other objects or surfaces.

Ancylus fluviatilis (Muller, 1774) 8x.European lakes. Interior and side view, apex on upper right.

 

Ferrissia tasmanica (Tenison Woods, 1876) New South Wales, Australia. 8x magnification.  

Ferrissia rivularis (Say, 1817) Most of North America.8x magnification.

 

Laevapex fuscus (Adams, 1841) Much of North America, lower elevations. Dark surface encrustations are typical. 8x magnification.  

Ancylus sp. Southwestern Brazil, rivers. Right image shows the inside surface of this translucent shell. 8x magnification.

 

Pilsbry and Becquaert, (1927) use the following classification for African freshwater limpets. They include 22 species in the genus Barnupia, endemic to Africa. Several of their nominal genera were not included in Banarescu's accounting. 

Ancylidae........."Ancylus".....Ferrissiinae........Ferrissia........Kincaidilla........Barnupia.....Pseudancylinae........Pseudancylus

     

Barnupia kimiloloensis Pilsbry and Becquaert, 1927. KimiloloRiver, Africa. 6 mm. Courtesy American Museum of Natural History.