Beddomeia briansmithi 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 its small umbilicus (as in B. turnerae); the long and tapering distal end of penis (not short as in other taxa) and in the  female genital system having 2 bends in the proximal coiled oviduct, and the oviduct and bursal duct are joined well in front of the posterior pallial wall.

Classification

Beddomeia briansmithi Ponder & Clark, 1993

Class Gastropoda

Infraclass Caenogastropoda

Order Littorinida

Suborder Rissoidina

Superfamily Truncatelloidea

Family Beddomeiidae

Genus Beddomeia Petterd, 1889

Original name: Beddomeia briansmithi Ponder & Clark, 1993. In 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. 

Type locality: Fern Creek, tributary of Carters Creek, 0.8 km ESE of Forester, on Conners Road, Tasmania.

Biology and ecology

In small stream, under stones, on weed on edges and on fern roots. 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 nearby locations in NE Tasmania.

Notes

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

This species is on the Tasmanian Threatened Species Protection Act 1995 as Vulnerable.

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.