Freshwater prawns

Code OT029999

Decapod crustaceans with a prominent rostrum and the abdomen bearing a tail fan. Eyes on stalks. A carapace completely covers the dorsal and lateral thorax. Legs long and thin, the second pair longer than the first and carrying moderately large chelae. The family occurs both in marine and fresh water.

Body shape is variable within this family and this key should work for freshwater but not necessarily for some marine genera. The fauna of inland waters includes the readily-identifiable long-armed prawns (Macrobrachium sp.) but as well three genera with a less marked difference between legs 1 and 2.

Palaemonidae can be distinguished from Parasticidae (crayfish) and Atyidae (shrimps) by the relative proportions of the first and second legs, by the relatively slender chelae on those legs, and by the third pair of legs lacking chelae. Non-decapod shrimp-like animals differ in these leg characters and in addition lack a carapace.

Palaemonidae live in running or still permanent waters, and away from the coast always in fresh water. The Australian species belong to the genera Macrobrachium, Palaemonetes, Leptopalaemon and Kakaducaris. Keys to genera and species are provided by Horwitz (1995).

References:

Horwitz, P. (1995) A Preliminary Key to the species of Decapoda (Crustacea: Malacostraca) found in Australian Inland Waters. Co-operative Research Centre for Freshwater Ecology Identification Guide No. 5., Albury, NSW.

Horwitz, P., Knott, B. and Williams, W.D. (1995) A Preliminary Key to the Malacostracan Families (Crustacea) found in Australian Inland Waters. Co-operative Research Centre for Freshwater Ecology Identification Guide No. 4., Albury, NSW.