Beddomeia forthensis 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.

Differs from other Beddomeia species in north central Tasmania in male genital system having the penis with the medial section parallel-sided (not tapering).

Classification

Beddomeia forthensis Ponder & Clark, 1993

Class Gastropoda

Infraclass Caenogastropoda

Order Littorinida

Suborder Rissoidina

Superfamily Truncatelloidea

Family Beddomeiidae

Genus Beddomeia Petterd, 1889

Original name: Beddomeia forthensis 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: Small tributary Forth River, on southern side of Geales Hill on Wilmot Road, Tasmania (41°16'37"S 146°14'30"E).

Biology and ecology

Under stones and dead leaves in stream.Egg capsules typical 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

This species occurs in a few small tributaries of the Forth River, mid-north 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 Rare (small population at risk).

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.