Ripalania queenslandica (E. A. Smith, 1882)

Diagnostic features

Shell thick with a smooth surface and brown-orange to olive-green in colour. Elongate conical in shape however the upper whorls are often corroded so that the shell is usually decollate. The suture is not impressed and flush with the whorls, The aperture is elongate oval to tear drop shaped with the basal part slightly flaring. There is no umbilicus. The operculum is oval and paucispiral. A brood pouch is located in the neck region of the head foot in females.

Classification

Ripalania queenslandica (E. A. Smith, 1882)

Common name: Queensland marsh snail

Class Gastropoda

Infraclass Caenogastropoda

Megaorder Cerithiimorpha

Order Cerithiida

Superfamily Cerithioidea

Family Thiaridae

Genus Ripalania Iredale, 1943 (Type species: Melania queenslandica E. A. Smith, 1882)

Original name: Melania queenslandica E. A. Smith, 1882. In Smith, E. A. (1883). On the freshwater shells of Australia. Journal of the Linnean Society 16:255 -317.

Type locality: Saltwater Creek, Cardwell, Queensland, near the coast; and Paroo River, Queensland.

Biology and ecology

Biology unstudied, but presumably a detritus feeder. Reproductive biology unstudied but related species brood larvae in a modified pallial oviduct.

Ripalania lives in creeks and streams with sandy or soft substrate bottoms, or among small stones and boulders, where it burrows in sediment and gravel. It prefers cool running freshwater streams in tropical rainforest areas and feeds on algae and detritus. Females are parthenogenic and reproduce ovoviviparously, i.e. releasing juveniles from the brood pouch as free swimming veligers.

Distribution

Tropical north-eastern Queensland.

Notes

The smooth, straight-sided spire which is almost always decollate, is characteristic of this species.

Further reading

Beesley, P. L., Ross, G. J. B. & Wells, A., Eds. (1998). Mollusca: The Southern Synthesis. Parts A & B. Melbourne, CSIRO Publishing.

Glaubrecht, M., Brinkmann, N. & Pöppe, J. (2009). Diversity and disparity ‘down under’: systematics, biogeography and reproductive modes of the ‘marsupial’ freshwater Thiaridae (Caenogastropoda, Cerithioidea) in Australia. Zoosystematics and Evolution 85: 199-275.

Glaubrecht, M. & Neiber, M. T. (2019). Thiaridae Gill, 1871 (1823). Pp. 86-89 in C. Lydeard & Cummings, K. S. Freshwater Mollusks of the World: a Distribution Atlas. Baltimore, John Hopkins University Press.

Iredale, T. (1943). A basic list of the fresh water Mollusca of Australia. Australian Zoologist 10: 188-230.

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.