Austropyrgus simsonianus (Brazier, 1875)

Diagnostic features

This species belongs to the Austropyrgus sparsus group, with members 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 simsonianus differs from the other species of this group in the following combination of characters: shell small to medium in size, spire outline straight, whorls convex, outer lip simple, inner lip distinctly separated from parietal wall; pallial vas deferens straight at prostate gland; penis pigmented on medial section only; oviduct straight distal to seminal receptacle.

Classification

Austropyrgus simsonianus (Brazier, 1875)

Class Gastropoda

Infraclass Caenogastropoda

Order Littorinida

Suborder Rissoidina

Superfamily Truncatelloidea

Family Tateidae

Genus Austropyrgus Cotton, 1942

Original nameAmnicola simsoniana Brazier, 1875. In Brazier, J. (1875). Descriptions of eight species of Australian and Tasmanian land and freshwater shells. Proceedings of the Linnean Society of New South Wales 1: 17–20.

Type locality: Brighton, Hobart, Tasmania.

Synonyms: Bythinia pontvillensis Tenison Woods, 1876. Bythinia dunrobinensis Tenison Woods, 1876. Bythinia dulvertonensis Tenison Woods, 1876.

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 has an extensive range throughout the drainage of the Derwent River, Tasmania.

Notes

Although most species of Austropyrgus are geographically isolated and have restricted ranges, some such as A. simsonianus have a rather wide range.

This species is not found in sympatry with any other species of Austropyrgus throughout its currently recognized range.

Further reading

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 28: 1–109.

Smith, B. J. & Kershaw, R. C. (1979). Field guide to the non-marine Molluscs of South-eastern Australia. Canberra, A.N.U. Press (as Pupiphryx dunrobinensis)

Smith, B. J. & Kershaw, R. C. (1981). Tasmanian Land and Freshwater Molluscs. Hobart, University of Tasmania (as Pupiphryx dunrobinensis).