Stenomelania Fischer, 1885

Diagnostic features

Shells are elongate, slender and solid with up to nine or more convex whorls. The whorls are usually corroded apically often giving the shell a truncated appearance. The suture is shallow or flush with the whorls. The surface of the shell is almost smooth, only a few spiral lines are visible. Occasionally there are weak axial ribs on the upper half of the whorls. The aperture is a broad oval. Some specimens have pronounced angulated shoulders on the whorls. There is no umbilicus. The colour varies from light brown to yellowish green with a few spots, speckles and flammulations on the apical whorls to dark brown or black. The operculum is oval and paucispiral

The edge of the mantle has numerous finger-like papillae, and a brood pouch is located in the head in females.

Classification

Stenomelania Fischer, 1885

Class Gastropoda

Infraclass Caenogastropoda

Megaorder Cerithiimorpha

Order Cerithiida

Superfamily Cerithioidea

Family Thiaridae

Genus Stenomelania Fischer, 1885

Type species: Melania aspirans Hinds, 1844

Original reference:  Fischer, P.H. 1885 (in) Tryon, G.W, (ed.) Manual of conchology, structural and systematic with illustrations of the species. Philadelphia: 701

Type locality: Fiji.

Biology and ecology

Occurs in stagnant as well as running waters in coastal rivers, creeks and reservoirs, commonly feeding on detritus. Usually found half buried in sand or amongst pebbles.

Distribution

Widespread through the south western Pacific. In Australia, the genus occurs across the tropical and subtropical north.

Notes

Some species of Stenomelania are similar in appearance to Melanoides tuberculata, and may be difficult to tell apart. However the two Australian species of Stenomelania can be separated by less distinct to absent spiral sculpture, usually a monochrome shell and, in one species, usually, a weak to strong shoulder just below the suture and in the other a concave upper part of the whorl.

Further reading

Bandel, K., Glaubrecht, M., & Riedel, F. (1997). On the ontogeny, anatomy, and ecology of the tropical freshwater gastropod Stenomelania (Cerithioidea, Thiaridae). Limnologica 27: 239-250.

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

Brandt, R. A. M. (1974). The non-marine aquatic Mollusca of Thailand. Archiv Für Molluskenkunde 105: 1-423.

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.

Maaß, N. & Glaubrecht, M. (2012). Comparing the reproductive biology of three “marsupial”, eu-viviparous gastropods (Cerithioidea, Thiaridae) from drainages of Australia’s monsoonal north. Zoosystematics and Evolution 88: 293–315.

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.