Similar to the Tasmanian G. atkinsoni but is flatter, smaller (maximum diameter usually about 5 mm) and the whorls are less acutely angled, and the aperture wider but not so high. In both species the keel is positioned slightly towards the 'base' (if viewed with the aperture on the right).
Brown (2001, p. 72) noted that "its penial morphology is like that of most species of Gyraulus known from mainland Australia, e.g. G. gilberti, rather than like that of G. meridionalis. Although this is known to be so for specimens of G. isingi from Valley Lake, Mt Gambier, one of the localities given in the original description, confirmation is needed from topotypical material. Since G. isingi does not appear to differ in any clear respect of shell or anatomy from the range of variation among the specimens from New South Wales and Queensland described here under G. gilberti and G. macquariensis, it is maintained as a distinct species with considerable doubt."
Gyraulus (Gyraulus) isingi (Cotton and Godfrey, 1932)
Class Gastropoda
Infraclass Heterobranchia
Megaorder Hygrophila
Order Lymnaeida
Superfamily Planorboidea
Family Planorbidae
Subfamily: Planorbinae
Genus Gyraulus Charpentier, 1837
Original name: Planorbis isingi Cotton & Godfrey, 1932. In Cotton, B. C. (1943). More Australian freshwater shells. Transactions of the Royal Society of South Australia 67: 143-148.
Type locality: Point McLeay, Lake Alexandrina, South Australia.
Synonyms: Glyptanisus caroli Iredale, 1943; Pygmanisus parvus Cotton, 1943.
This species lives on aquatic vegetation and stones in temperate ponds, streams and rivers. Feeds on detritus. Egg mass presumably a jelly strip containing small eggs. Development direct.
Brown (1981 & 2001) described the anatomy of this species.
South-eastern South Australia and southern Victoria.
According to Brown (2001) this species may be conspecific with G. gilberti, the latteroccurring further north. He noted that (Brown 2001: 72) "Since G. isingi does not appear to differ in any clear respect of shell or anatomy from the range of variation among the specimens from New South Wales and Queensland described here under G. gilberti and G. macquariensis, it is maintained as a distinct species with considerable doubt."
Brown, D. S. (1981). Observations on the Planorbidae from Australia and New Guinea. Journal of the Malacological Society of Australia 5: 67-80.
Brown, D. S. (1998). Freshwater snails of the genus Gyraulus (Gastropoda: Planorbidae) in Australia: the taxa of Tasmania. Molluscan Research 19: 105-154.
Brown, D. S. (2001). Freshwater snails of the genus Gyraulus (Planorbidae) in Australia: taxa of the mainland. Molluscan Research 21: 17-107.
Hubendick, B. (1955). Phylogeny of the Planorbidae. Transactions of the Zoological Society of London 28: 453-542.
Smith, B. J. (1992). Non-marine Mollusca. Pp. i-xii, 1-408 in W. W. K. Houston. Zoological Catalogue of Australia, 8. Canberra, Australian Government Publishing Service.
Smith, B. J. and Kershaw, R. C. (1979). Field guide to the non-marine molluscs of south eastern Australia. Australian National University Press, Canberra, Australia.
