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 Major Groups | Crustacea (crustaceans) | Conchostraca (clam shrimps)

Conchostraca (clam shrimps)

Major Group: Crustacea
Minor Group: Conchostraca

Descriptive Features:

  • bivalved carapace, enclosing whole animal, growth lines visible OR absent
  • 10 to > 30 pairs of trunk appendages, pairs 1 or 2 clawed (males), pairs 9-11 modified to carry eggs (females)
  • conspicuous head
  • short paired uniramous antennules, longer paired biramous antennae used for swimming
  • rostrum present on head anteriorly, small antero-dorsal structure present or absent
  • sessile compound eyes, dorsally, close together
  • Total length: up to 25 mm
  • Limnadopsis sp. 


    Cyzicus sp. 


    Taxonomic Checklist: Families
    Cyclestheridae: Cyclestheria hislopi Baird
    Leptestheriidae: Eoleptestheria ticinensis Balsamo-Crivelli
    Lynceidae: Lynceus

    Distribution: Australia wide. All but 1 species (Cyclestheria hislopi) are endemic.

    Sensitivity Rating: SIGNAL grade 1

    Functional Feeding Group: filtering collectors


    Pine Lake, Paroo NSW

    Ecology: Instream habitat: Conchostraca species occur in ponds, dams, rock pools, temporary pools, turbid freshwater clay pans and permanent lakes.
    Feeding ecology: Clam shrimps are omnivores and filter feeders. Conchostracan blooms can become a problem in aquaculture ponds by reducing the production of other zooplankton and phytoplankton eaten by juvenile fish.
    Habit: Clam shrimps are free swimming, skimming slowly along the substratum.
    Life history: Eggs are carried in a brood pouch until the female moults or dies. Species from temporary waters have only one generation per wet period. Eggs require a drying period before hatching and so are resistant to desiccation.


    Information Sources: Timms 2009a, 2009b, Timms & Richter 2009, Richter & Timms 2005, Williams 1980, Ingram et al. 1997, Hawking & Smith 1997
    Key to Families: Timms 2009b
    Key to Genera: Timms 2009b
    Timms & Schwentner 2012 (Limnadiidae, world) refers to  Rogers et al. 2012 (Limnadiidae, world, incomplete)
    Key to Species: Timms 2009a (Limnadopsis)