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 nitidus differs from the other species of this group in the following combination of characters: shell small to medium in size, with straight spire outline and convex whorls; seminal vesicle tightly coiled over stomach; pallial vas deferens straight at prostate gland; coiled oviduct and bursal duct join well behind posterior pallial wall.
Austropyrgus nitidus (Johnston, 1879)
Class Gastropoda
Infraclass Caenogastropoda
Order Littorinida
Suborder Rissoidina
Superfamily Truncatelloidea
Family Tateidae
Genus Austropyrgus Cotton, 1942
Original name: Bithynella nitida Johnston, 1879. In Johnston, R. M. (1879). Further notes on the fresh-water shells of Tasmania (with a description of new species). Papers and Proceedings of the Royal Society of Tasmania 1877: 19–29.
Type locality: Thunder and Lightning Bay, Cape Barren Island, Bass Strait, Tasmania (Quaternary fossil deposits).
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.
This species is found in the small streams and rivers of Flinders and King Islands and some of the other smaller islands of Bass Strait.
Although most species of Austropyrgus are geographically isolated and have restricted ranges, a few - such as A. nitidus - have wider ranges. This is the only species of Austropyrgus living on the Bass Strait islands.
This species was named from Quaternary deposits but the living material from the same area is very similar and treated as the same species by Clark et al. (2003).
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.