Viviparous river snails
Class Gastropoda: Subclass Prosobranchia: Order Monotocardia.
Widespread family absent from South America.
Found in the large drainage basins of the central and northern regions, and in much of south-eastern Australia. Absent from Tasmania, southern Victoria and south-western Australia.
Six species in three genera are recorded from Australia and many others occur in South-east Asia. There appears to be no endemic species. Mainly riverine in habit, a small population of a recently introduced aquarium species occurs in a few ponds, as for example, in Centennial Park Lake, Sydney.
Many viviparids appear to be able to resist drought, possibly by burrowing themselves in drying mud and sealing the operculum shut. Some species are widely used in aquaria. The Javanese genus Bellamya is used to feed ducks, and B. javanica can serves as an intermediate host for Trematodes ( Echinostoma ).
Until recently, the species Notopala hanleyi was thought to have been driven extinct by a combination of flow regulation, high turbidity and introduced common carp. However, populations have since been found persisting in irrigation pipelines on the lower River Murray, where they feed on the accumulation of microbial and other organic matter on the inner wall and occasionally cause blockages.
Smith, B.J. (1996) Identification keys to the Families and Genera of Bivalve and Gastropod Molluscs found in Australian Inland Waters . Cooperative Research Centre for Freshwater Ecology Identification Guide No. 6., Albury, NSW.