|
< Previous family introduction |
|
|||||
 |
Family Hydrobiidae Hydrobiids
|
|||||
|
The Hydrobiidae is a large family of freshwater, brackish water and estuarine marine snails. It has a worldwide distribution, and is well represented in Australia and New Zealand. There are about 200 species described from Australia, mostly freshwater species from the south-eastern part, including Tasmania. Species also occur on Howe Island and in the artesian springs of northern South Australia and southern Queensland. A few undescribed species are known from groundwater in NW Australia. Many of the species have very restricted ranges, being found in a single spring or water body. For the family at large, shells are small, under 10 mm and usually under 5 mm, with a variety of shapes and forms, from long and slender to flat spired. Sculpture is diverse, varying from smooth to axially ribbed and less often spirally ribbed. For the family as a whole, hydrobiids cannot be characterised and distinguished on external and habitat characters alone, although they are readily identified using anatomical features. Hydrobiids live in a wide variety of habitats from estuarine mudflats and mangroves to mountain lakes, caves, creeks, rivers, in artesian springs and in subterranean groundwater. Only three species of marine hydrobiids occur in NSW, and only these are treated here. These occur in estuarine and brackish water environment, including mangroves, high up on the shore and are often abundant. The three species were all described in the 19th century, but it was not until the work of Ponder et al. that they were well differentiated and their ecology and distribution was investigated. Family References Ponder, W.F. & Clark, G.A. (1988) A morphological and electrophoretic examination of "Hydrobia buccinoides", a variable brackish-water gastropod from temperate Australia (Mollusca: Hydrobiidae). Australian Journal of Zoology 36: 661-698 Ponder, W.F., Colgan, D.J. & Clark, G.A. (1991) The morphology, taxonomy and genetic structure of Tatea (Mollusca: Gastropoda: Hydrobiidae), estuarine snails from temperate Australia. Australian Journal of Zoology 39: 447-497 Coverage Only the three marine species of the family are considered here. Identification Notes Hydrobiid shells are difficult to distinguish from related families on shell characters alone. |