Diagnostic features

This species belongs to the Austropyrgus sparsus group, whose members are characterised by the following shell features: small to medium-sized shells, conical, with convex to slightly convex whorls. In females, the coiled oviduct is of an inverted U-shape or with two or more bends, loops or twists.

Austropyrgus halletensis differs from other members of the group in the following combination of characters: shell small to medium in size, with slightly convex to convex whorls and outer lip with slight reflection; coiled oviduct and bursal duct join well behind posterior pallial wall; female genital opening of medium length.

Classification

Austropyrgus halletensis Clark, Miller & Ponder, 2003

Class Gastropoda

Infraclass Caenogastropoda

Order Littorinida

Suborder Rissoidina

Superfamily Truncatelloidea

Family Tateidae

Genus Austropyrgus Cotton, 1942

Original name: Austropyrgus halletensis Clark, Miller & Ponder, 2003. In Clark, S. A., Miller, A. C. & Ponder, W. F. (2003). Revision of the snail genus Austropyrgus (Gastropoda: Hydrobiidae): A morphostatic radiation of freshwater gastropods in southeastern Australia.  Records of the Australian Museum Supplement 28: 1–109.

Type locality: Small creek 0.5 km east of Hallet, on Burra-Peterborough Road, South Australia.

Biology and ecology

In streams on water weeds, hard substrata (rocks etc.) and crawling on litter and sediment. Can be locally abundant. Assumed to feed by scraping bacteria and microalgae. Lay solitary capsules containing a single egg. Direct development.

Distribution

This species is currently only known from the type locality in the central portion of the Flinders Ranges, South Australia.

Notes

Most species of Austropyrgus are geographically isolated and have restricted ranges, and this one is no exception. This species is not found in sympatry with any other species of Austropyrgus.

Further reading