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: Diverse in rivers of the Southeast United States. Many genera world wide. Several alternative classifications were considered by Banarescu (1990), who finally settled with the following subfamilies and genera: Pleurocerinae Pleurocera; American interior Elimia; widespread, eastern North America Lithasia; Ohio River drainage Leptoxis; widespread, eastern North America Io; endemic to Tennessee River 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 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, Syrnolopsidae Latin American Pleuroceridae   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 Pleuroceridae   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.         Two specimens obtained from diferent sources, identified as Brotia costula (Rafinesque, 1833), (left), and Brotia costulata (Rafinesque, 1833), (right), from Malaysia, and Bangladesh, 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 additional subspecies 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 family.] 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. Brandt's description reads; Shell large for family and genus; it is the largest representative of the family in Thailand and one of the largest freshwater species of the superfamily. Shell elongately turreted, solid to thick, covered with a dark brownish or olive-brown periderm. The apex is generally truncate thus leaving 4-8 of the 9-12 whorls. The sculpture consists of numerous spiral grooves which are weaker on the upper half of the body whorl and may be even obsolete on the middle and postnuclear whorls. The upper spiral ridges may carry nodules which, when developed, mat appear as short spines. The axial ribs are more or less strongly developed; they never attain the suture and do not reach beyond the periphery of the body whorl. The variability with regard to size shape and costulation caused Bensons choice of the name. The shells are either unicoloured or show 1 - 3 brown spiral bands. - Aperture brown or milky white within. Peristome greatly produced at the base. - Operculum almost circular, with 5 whorls. Size A 55-74 mm; D 22-31 mm. Animal dark grey with orange ot yellow pigment spots. Females with many small conical embryonic shells in the brood pouch. The reproductive organs of the male (about 3% in examined populations seem to have no functional gonads. ... Rhachis with narrow glabella and large middle cusp on the cutting edge. On either side of it are 2 curved, finger shaped small cusps. The irregularly shaped laterals have the cusp formula 1-1-1(2), the marginals have 2 cusps. Type locality River Ganges. There is a lot more information if needed in this paper. Of interest Costula peninsularis has been reported as infected with cercariae of Paragonimus westermani in Malaysia, but not in Thailand.           Semisulcospira libertina (Gould, 1858) Taiwan   Semisulcospira reticulata Kajiyama and Habe, Japan   Biwamelania japonica (Smith, 1876) Lake Biwa, Japan Home Page | Sitemap