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Beddomeia topsiae Ponder and Clark, 1993

Diagnostic features

Species included in the B. bellii group are small to medium-sized (2.3-3.0 mm in length), ovate-conic to ovate and usually have a columella swelling. The penis is simple (as in B. bellii and B protuberata) or with a lenticular brown gland in the middle. Species in this group are restricted to north western Tasmania.

B. topsiae is distinguished from the four other related species B.mesibovi, B.salmonis, B. gibba and B. [1] [2]fultoni by the following combination of anatomical characters: a short papilla on the penis, the ventral channel of the capsule gland having a well-developed anterior vestibule and a very small second bend on the proximal part of the coiled oviduct.

Classification

Beddomeia topsiae Ponder and Clark, 1993

Class Gastropoda

Subclass Caenogastropoda

Order Littorinimorpha

Superfamily Truncatelloidea

Family Tateidae

Genus Beddomeia Petterd, 1889

Original name: Beddomeia topsiae Ponder and Clark, 1993 in Ponder, W.F., Clark, G.A., Miller, A. & 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 Williamsons Creek on Trowutta Road, approximately 1km south of Roger River, Tasmania.

Biology and ecology

On rocks and litter in small stream.Egg capsules white and 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 is only known from its type locality.

Notes

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

This species was found in a small stream where it lives with a species of Austropyrgus.

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