This species belongs to the Austropyrgus cooma group, whose members are characterised by generally pupiform to conical, small to medium-sized shells, where the last whorl and base are evenly convex.
A. parvus differs from other members of the group in the following combination of characters: shell small, with convex spire outline and convex whorls; pallial vas deferens slightly undulating at prostate gland; penis pigmented medially and distally; albumen gland about ¼–½ in front of the posterior pallial wall.
This species is sympatric with A. salvus, from which it can be separated by its smaller, narrower shell.
Austropyrgus parvus Clark, Miller & Ponder, 2003
Class Gastropoda
Infraclass Caenogastropoda
Order Littorinida
Suborder Rissoidina
Superfamily Truncatelloidea
Family Tateidae
Genus Austropyrgus Cotton, 1942
Original name: Austropyrgus parvus 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: Western side of Newlands Cascades, Franklin River, opposite downstream end of rock shelter, Tasmania.
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.
This species is currently only known from two locations a short distance apart along the lower Franklin River, southwest Tasmania.
Most species of Austropyrgus are geographically isolated and have restricted ranges, and this one is no exception.
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.
