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Beddomeia fromensis Ponder & Clark, 1993

Diagnostic features

Species of the B. hullii group are found in the northern half of Tasmania. Their shells are small (1.7-3.7 mm in length; most less than 3.5 mm), simple, ovate-conic to broadly conic, with a thin inner lip and no columellar bulge. The periphery of the last whorl of the shell is rounded, subangled or angled and the penis simple.

This species differs from other members of the group in having a narrower shell being, with closed umbilicus; pallial cavity with fewer ctenidial filaments; male genital system with kidney-shaped prostate gland (pyriform in other taxa), undulating pallial vas deferens; female genital system with pallial oviduct with simple ventral channel.

Classification

Beddomeia fromensis Ponder & Clark, 1993

Class Gastropoda

Subclass Caenogastropoda

Order Littorinimorpha

Superfamily Truncatelloidea

Family Tateidae

Genus Beddomeia Petterd, 1889

Original name: Beddomeia fromensis Ponder & Clark, 1993 in Ponder, W.F., Clark, G.A., Miller, A.C. and Toluzzi, A. (1993). On a major radiation of freshwater snails in Tasmania and eastern Victoria: a preliminary overview of the Beddomeia group (Mollusca: Gastropoda: Hydrobiidae). Invertebrate Taxonomy 7: 501-750.

Type locality: Small tributary of Frome River, on north-western side, 0.5 krn northeast along Greenstone Road, Tasmania.

Biology and ecology

Occurs in small stream(s) under dead leaves and under pieces of wood. Egg capsules presumably like those of other species of Beddomeia - dome-shaped, with broad attachment base, covered with minute, mainly white sand grains and other fragments and containing a single egg. Development direct.

Distribution

Only known from type locality and a few nearby locations in north-eastern Tasmania.

Notes

All species of Beddomeia are geographically isolated and have restricted ranges.

This species is on the Tasmanian Threatened species list of Invertebrate Animals as Endangered.

Further reading

Ponder, W. F., Clark, G. A., Miller, A. C. & Toluzzi, A. (1993). On a major radiation of freshwater snails in Tasmania and eastern Victoria: a preliminary overview of the Beddomeia group (Mollusca: Gastropoda: Hydrobiidae). Invertebrate Taxonomy 7: 501-750.