Species in the B. tasmanica group have small shells (length 1.2-2.8 mm) with a depressed spire and open umbilicus. The penis is simple.
This species differs from other members of the group in its small shell (< 2 mm in length and width), about equal in length and width, with a prominent umbilicus; the mantle cavity has an arched rectum on the roof and the radula has the dorsal edge of the central teeth with a shallow indentation.
Beddomeia tasmanica (Tenison Woods, 1876)
Class Gastropoda
Infraclass Caenogastropoda
Order Littorinida
Suborder Rissoidina
Superfamily Truncatelloidea
Family Beddomeiidae
Original name: Valvata tasmanica Tenison Woods, 1876. In Woods, J. E. Tenison (1876). On the freshwater shells of Tasmania. Papers and Proceedings of the Royal Society of Tasmania 1875: 66-82.
Type locality: ‘Small trickling stream in Gould's Country’.
Under stones and rocks in deeper streams. The white egg capsules are laid on the undersides of rocks and are 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.
This species is known from a small number of streams (Groom River catchment) in Goulds Country and its surroundings, north-eastern Tasmania.
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).
