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 macaulayidiffers from other members of the group in the following combination of characters: shell small to medium in size, with straight spire outline, outer lip heavily thickened; renal gland about ¼ in pallial roof, circular; coiled oviduct with initial U orientated longitudinally backwards.
This species is not found in sympatry with any other species of Austropyrgus. However, it is commonly found with the introduced tateid Potamopyrgus antipodarum from which it differs in a number of characters including its smaller size, thickened aperture and pegs on the inner side of the operculum.
Austropyrgus macaulayi Clark, Miller & Ponder, 2003
Class Gastropoda
Infraclass Caenogastropoda
Order Littorinida
Suborder Rissoidina
Superfamily Truncatelloidea
Family Tateidae
Genus Austropyrgus Cotton, 1942
Original name: Austropyrgus macaulayi 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: Dunns Creek at Bittern-Dromana Road, Red Hill, south of Frankston, Victoria.
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 found in small streams on the eastern side of Port Phillip Bay, Victoria.
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.