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.
Beddomeia topsiae is distinguished from the four other related species B. mesibovi, B. salmonis, B. gibba and B. fultoni [1] [2][1] [2] 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.
Beddomeia topsiae Ponder & Clark, 1993
Class Gastropoda
Infraclass Caenogastropoda
Order Littorinida
Suborder Rissoidina
Superfamily Truncatelloidea
Family Beddomeiidae
Original name: Beddomeia topsiae Ponder & 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.
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.
This species is only known from its type locality.
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 Protection Act 1995 as Rare (small population at risk).
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.
