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 Major Groups | Cnidaria (hydra, jelly fish) | Hydrozoa (hydra, jellyfish) | Olindiidae

Craspedacusta sowerbyi

Major Group: Cnidaria
Minor Group: Hydrozoa (Pennak 1989, ABRS 2004)
Order: Hydrozoa (Williams 1980) or Hydroida (Pennak 1989, ABRS 2004)
Genus: Craspedacusta
Species: sowerbyi
This family is represented in Australian freshwaters by a single species, Craspedacusta sowerbyi Lankester. There is some discrepancy in the literature about the taxonomic level of Hydrozoa. This does not affect the identification of Olindiidae.

Descriptive Features:

  • free swimming, bell-shaped
  • manubrium, 4 radial canals,1 circular canal forming gastrovascular cavity
  • bell margin bears 50 -500 solid tentacles of varying length
  • marginal bulbs unitentacular
  • bell margin also with 60 - 100 statocysts, or more
  • velum is thick
  • nematocysts abundant around the mouth, at bell margin and on the tentacles
  • Size: 5 – 22 mm

      Craspedacusta sowerbyi, ventral view


      Craspedacusta sowerbyi, hydroid

      Taxonomic Checklist: Craspedacusta sowerbyi Lankester

      Distribution: all states

      Sensitivity Rating: none

      Functional Feeding Group: predators


      Murray River at Cottadidda State Forest, NSW

      Ecology: Instream habitat: Craspedacusta sowerbyi is usually found floating near the surface of large freshwater bodies.
      Feeding ecology: All cnidarians are predators feeding on minute animals such as cladocerans and copepods. They catch their prey with tentacles armed with stinging nematocysts.
      Life history: The major life cycle stage of the Craspedacusta sowerbyi is a small, circular medusa about 2.5 cm in diameter.


      Information Sources: Williams 1980, Pennak 1989, Gooderham & Tsyrlin 2002

      life stages 

      A–colony of hydroids
      B–hydroid with planulalike bud
      C–hydroid with medusa bud


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