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 Major Groups | Crustacea (crustaceans) | Ostracoda (seed shrimps)

Ostracoda (seed shrimps) Podocopida

Major Group: Crustacea
Minor Group: Ostracoda
Order: Podocopida

Descriptive Features:

  • bivalved carapace, jointed in dorsal region, encloses whole animal
  • carapace surface smooth, sculptured, grooved, pitted or setose, growth lines not present
  • indistinct body segmentation
  • 7 pairs of appendages, respectively, antennules, antennae, mandibles, maxillules, maxillae, thoracopods (2 pairs)
  • antennules and antennae uniramous, bearing several long setae, exopodites reduced
  • single or double eye spot at base of antennules, or absent
  • each mandible with 3-segmented palp and branchial plate
  • conspicuous branchial plate at proximal end of each maxilla
  • abdomen greatly reduced terminating in 2 or more, less developed caudal rami, articulated to the posterior of the trunk
  • Total length: 410 Ám -4 mm

    Newnhamia sp.


    Ostracoda sp.

    Taxonomic Checklist: Families
    Ilyocyprididae Ilyocypris 
    Leptocytheridae Leptocythere lacustris De Deckker
    Notodromadidae Newnhamia 
    Darwinulidae Darwinula
    Cypridopsidae Cypridopsis

    Distribution: Australia wide

    Sensitivity Rating: none

    Functional Feeding Group: filtering collectors


    Broken River, Benalla Vic

    Ecology: Instream habitat: Seed shrimps occur in fresh to hyper saline, lotic and lentic, permanent and temporary waters. They are mostly free living, often found amongst macrophytes or in muddy sediments. However, Entocytheridae species are commensal on crayfish (Decapoda), not harming the host.
    Feeding ecology: Free living Ostracoda use the antennules and antennae for filter feeding on organic detritus and algae, and for locomotion. In turn seed shrimps are eaten by other invertebrates and juvenile fish.
    Habit: Typically the valves of the carapace gape and the animal protrudes but when disturbed the valves shut tight to protect the animal.
    Life history: Some ostracod species lay eggs on submerged objects or substratum whilst other species hold them in brood pouches. Eggs can withstand physical and chemical extremes. Eggs hatch to a nauplius larva with only three pairs of appendages, antennules, antennae and mandibles. Juvenile ostracods moult up to eight times before reaching maturity, adults do not moult. Both sexual dimorphism and parthenogenesis are present with environmental factors influencing which mode of reproduction dominates.


    Information Sources: Karanovic et al. 2012, Dedekker & Shearn 2012, Karanovic 2005, De Decker 2002, 1981 a, b, c, Williams 1980, Ingram et al 1997, Davis & Christidis 1997, Gooderham & Tsyrlin 2002, Halse & McRae 2004
    Key to families: De Deckker 2002
    Key to Genera: Karanovic et al. 2012 (Cyprididae: Scottiinae, world)
    Karanovic 2005 (Candonidae: Candoninae)
    Key to Species: Karanovic et al. 2012 (Cyprididae: Scottiinae, world)
    Karanovic 2005 (Candonidae: Candoninae, including stygbiont species)
    Karanovic 2009 (Limnocytheridae: Timiriaseviinae)