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Beddomeia averni 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 closely resembles B. fallax in shell characters, but differs in having the bursal duct and oviduct join in front of the posterior pallial wall.

Classification

Beddomeia averni Ponder & Clark, 1993

Class Gastropoda

Subclass Caenogastropoda

Order Littorinimorpha

Superfamily Truncatelloidea

Family Tateidae

Genus Beddomeia Petterd, 1889

Original name: Beddomeia averni Ponder & Clark, 1993 in Ponder, W.F., Clark, G.A., Miller, A.C. and 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 stream, 3 km east of Preston, West Gawler, Tasmania.

Biology and ecology

In leaf litter and gravel and in fern mats & weed attached to rock shelf in stream and small trickle. Egg capsules unknown but assumed to resemble those of other Beddomeia species (dome-shaped, with broad attachment base, covered with minute, mainly white sand grains and other fragments; contain a single egg). Development is direct.

Distribution

Only known from type locality near Preston, West Gawler, Tasmania.

Notes

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

Occurs sympatrically with two species of Austropyrgus.

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

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.