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Beddomeia angulata Ponder and 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.

The angled periphery of the last whorl of this taxon gives this conical shell a very distinctive shape. In general size and shape it is similar to the B. lodderae but differs from that taxon in the shape of the bursa copulatrix and the position of its duct.

Classification

Beddomeia angulata Ponder and Clark, 1993

Class Gastropoda

Subclass Caenogastropoda

Order Littorinimorpha

Superfamily Truncatelloidea

Family Tateidae

Genus Beddomeia Petterd, 1889

Original name: Beddomeia angulata 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: Tributary of Rapid River, 18.2 km south of Holden Road, along Pipeline Road, 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

This species occurs in a tributary of Rapid River, Tasmania.

Notes

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

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.