Shell small (up to about 2mm in diameter), trochiform to depressed-trochiform, umbilicate, smooth, with only sculpture weak axial growth lines. Aperture oval, peristome thin, no external varix; outer lip simple, with thin edge. Periostracum smooth, thin. Operculum oval, nucleus subcentral, thin, simple. Penis with swollen basal portion and tapering distal portion that is usually pigmented; coiled anti-clockwise when at rest.
Genus Trochidrobia Ponder, Hershler & Jenkins, 1989
Original reference: Ponder, W. F., Hershler, R. & Jenkins, B. (1989). An endemic radiation of hydrobiid snails from artesian springs in northern South Australia: their taxonomy, physiology, distribution and anatomy.Malacologia 31: 1-140.
Type locality: Blanche Cup Spring, west of Lake Eyre South, South Australia.
Abundant in most of the springs in which they occur, living in a variety of microhabitats and appear to be particularly abundant in shallow, firm-bottomed outflows. Egg capsules are spherical, cemented in umbilicus of shell with mucus (known only in T. punicea).
Artesian springs between Marree and Oodnadatta, northern South Australia.
The species contained in Trochidrobia are similar in shell and opercular characters to Posticobia. However, Trochidrobia species have more depressed shells, and lack the peripheral keel typical of some specimens of Posticobia.
Beesley, P. L., Ross, G. J. B. & Wells, A., Eds. (1998). Mollusca: The Southern Synthesis. Parts A & B. Melbourne, CSIRO Publishing.
Murphy, N. P., Guzik, M. T., Cooper, S. J., & Austin, A. D. (2015). Desert spring refugia: museums of diversity or evolutionary cradles?. Zoologica Scripta 44: 693-701.
Ponder, W. F. (2004). Endemic aquatic macroinvertebrates of artesian springs of the Great Artesian Basin—progress and future directions. Records of the South Australian Museum Monograph Series 7: 101-110.
Ponder, W. F., Eggler, P. E. & Colgan, D. J. (1995). Genetic differentiation of aquatic snails (Gastropoda: Hydrobiidae) from artesian springs in arid Australia. Biological Journal of the Linnean Society 56: 553-596.
Ponder, W. F., Hershler, R. & Jenkins, B. (1989). An endemic radiation of Hydrobiidae from artesian springs in northern South Australia: their taxonomy, physiology, distribution and anatomy. Malacologia 31: 1-140.