The shell shape varies from depressed with a keel and fringe to high-whorled with only an obtuse angle on the periphery. The spiral sculpture also varies within and between samples, from very weak spiral ridges and is sometimes reticulate. Some strongly sculptured forms are similar to G. hesperus but that species differs anatomically (prostate with more lobes) and has a more elevated shell.
Gyraulus (Gyraulus) essingtonensis (E. A. Smith, 1882)
Class Gastropoda
Infraclass Heterobranchia
Megaorder Hygrophila
Order Lymnaeida
Superfamily Planorboidea
Family Planorbidae
Subfamily: Planorbinae
Genus Gyraulus Charpentier, 1837
Original name: Planorbis essingtonensis E. A. Smith 1882. In Smith, E.A. (1882). On the freshwater shells of Australia. Journal of the Linnean Society of London, Zoology 16: 255-316.
Type locality: Port Essington, Northern Territory.
Synonym: Glyptanisus coranus Iredale, 1943.
This species lives in water weeds and other vegetation in waterholes, ponds, billabongs, swamps and sluggish streams and rivers from the Red Centre to tropical northern Australia. Feeds on detritus. Egg mass presumably a jelly strip containing small eggs. Development direct.
Brown (2001) described the anatomy of this species.
This species occurs in northern and central Australia, from the Gulf of Carpentaria to Pilbara, possibly extending as far south as Perth - it also extends very far inland, to the Northern Territory-South Australian border.
This species exhibits extreme variability in size, sculpture, peripheral angulation and whorl count; it could possibly be conspecific with G. gilberti according to Brown (2001).
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.
Willan, E. C. & Kessner, V. (2021). A conspectus of the freshwater molluscs of the Daly River catchment, Northern Territory. Northern Territory Naturalist 30: 108-137.
