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 interior Elimia; widespread, eastern North America Lithasia; Ohio River drainage Leptoxis; widespread, eastern North America Io; endemic to Tennessee River and tributaries Gyratoma; endemic to Coosa River drainage, largely extinct Juga; American far West and Northwest. Holandriana; Danube River basin Namruta; Japan Amnipila; central Mexico Pachychilus; Central and much of South America Doryssa; eastern South America Potadoma; central Africa Potadomoides; southeastern Africa Pachymelania; central Africa Lavigeriinae Semisulcospira; East Asia and Japan Lavigeria; Lake Tanganyika Paludominae Paludomus; India and Southeast Asia Chlorostracia; part of Burma Cleopatra; Widespread Central Africa and Nile Pseudocleopatra; tropical West Africa additional genera endemic to Lake Tanganyika Paramelaniinae = Tiphobiinae Tiphobia; Lake Tanganyika. Elimia catenaria (Say, 1822) Atlantic coastal plain rivers 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 neritoides Reeve 1847. Sri Lanka. Approx. natural size. Large, thick shell, patterns visible 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 reticulata Kajiyama and Habe, Japan   Biwamelania japonica (Smith, 1876) Lake Biwa, Japan Home Page | Sitemap