Sand fleas

Code OP069999

One of three Australian families in the superfamily Crangonyctoidea, which are the dominant amphipods of cold, running freshwaters in Australia. Crangonycoidea can be distinguished from other Australian aquatic Amphipoda by a combination of features: (1) the antennules are the same length as or longer than the antennae; (2) the accessory flagellum of the antennule is conspicuous with 2 or more articles, although it is short; (3) all three uropods are well-developed; (4) the third uropod carries a 1-2 segmented outer ramus of which segment 2 may be well developed or very short, and almost always an inner ramus which often is shorter than the outer ramus; (5) the telson is cleft or notched (except in one species of Paramelitidae); (6) the mandible has a palp.

Paramelitidae comprises 27 described species in 11 genera. The antennules either are the same length as the antennae or are longer. There either are no sternal gills (seven spp.; six from Tasmania, one from the Millstream system, Pilbara region, WA) or else the sternal gills are simple, sausage-shaped structures (20 spp., some widespread in south-eastern Australia). In one West Australian species possessing sternal gills the telson is entire, in all others it is at least partially cleft. The inner ramus of uropod 3 varies. It can be as long as 2/3 the length of the outer ramus, or shorter, or absent. There are no posterior distal rugosities on the gnathopods (contrast Neoniphargidae).

Distribution: Mainly south-east Australia and Tasmania with isolated species in the Chillagoe Caves, Qld (1 sp.), the south-west of WA (3 spp.), and Pilbara (1 sp.).

References:

Bradbury, J. H., and W. D. Williams. (1999) Key to and checklist of the inland aquatic amphipods of Australia . Technical reports of the Australian Museum, number 14.

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.

Williams, W. D. (1980) Australian Freshwater Life . Macmillan.