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 niger differs from the other species of this group in the following combination of characters: shell small to medium in size, conical, with straight to weakly convex spire outline; faecal pellets orientated obliquely or transversely; pallial vas deferens strongly undulating at prostate gland; anterior end of capsule gland blunt.

Classification

Austropyrgus niger (Quoy & Gaimard, 1834)

Class Gastropoda

Infraclass Caenogastropoda

Order Littorinida

Suborder Rissoidina

Superfamily Truncatelloidea

Family Tateidae

Genus Austropyrgus Cotton, 1942

Original name: Paludina nigra Quoy & Gaimard, 1834. In Quoy, J.R., & Gaimard, J.-P. (1834). Vogage de Découvertes de l’Astrolabe exécuté par Ordre du Roi, Pendant les Années 1826– 1827, 1828, 1829, sous le commandement de M. J. Dumont d’Urville. Vol. 3, part 1. Pp. 1-366. Paris: J. Tastu Zoologie.

Type locality: Small stream flowing into the d’Entrecasteaux Channel, Tasmania.

Biology and ecology

On water weeds, hard substrata (rocks etc.) and crawling on sediment. Can be locally abundant. Assumed to feed by scraping bacteria and microalgae. Presumed solitary capsules with single egg. Direct development.

Distribution

This species is found in the small streams along the d’Entrecasteaux Channel, south-eastern Tasmania.

Notes

Although most species of Austropyrgus are geographically isolated and have restricted ranges, a few such as A. niger have wider ranges.

This species is the type species of the genus and the first tateid to be named from Australia. It was wrongly referred to the genus Potamopyrgus and used as the Australian name for P. antipodarum (see Ponder 1988 for details).

Further reading