Clam shrimps

Code OF039999

A family of the Conchostraca (clam shrimps). Conchostraca are placed along with the orders Notostraca, Anostraca and Cladocera in the class Branchiopoda, a name which refers to the foliose trunk appendages which function as gills. In Conchostraca the body is completely encased in a hinged, bivalved carapace. The antennules are one-branched (uniramous), often only one-segmented, and do not protrude from the carapace. The antennae are two-branched (biramous), project, and functioning in movement, grasping, and/or adhering to a surface. There are 10-many trunk appendages, most or all of which are flattened and function as gills. In males the first one-two pairs of trunk appendages carry claspers which are used in mating.

Conchostracans are important members of the temporary pool community but some occur in the littoral zone of larger bodies of water. Most species have drought resistant eggs. The Australian fauna comprises the families Cyzicidae, Limnadiidae, Cyclestheriidae and Lynceidae.

CYCLESTHERIIDAE: The antennules are 1-segmented, there is no frontal organ on the head (compare Limnadiidae), and the eyes are fused together. The carapace shows few growth lines (less than 10). In males, claspers occur only on the first pair of trunk appendages. A furca is present. Cyclestheriais represented in Australia by a single non-endemic species C. hislopi, which occurs in Queensland and New South Wales.

Reference:

Williams, W.D. (1980) Australian Freshwater Life: The Invertebrates of Australian Inland Waters.The Macmillan Company of Australia, Melbourne.