University of Tasmania, Australia

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Sars 1903


Phylum Arthropoda
Subphylum Crustacea
Class Maxillopoda
Subclass Copepoda
Order Calanoida


  • Includes 43 families and approximately 2000 species (marine and freshwater).

Distinguishing characteristics

  • Long, usually slender body.
  • Long antennules.
  • Geniculate antennae in males.
  • Gymnoplean tagmosis (boundary between fifth pedigerous somite and genital somite).
  • Fifth leg biramous .


  • Worldwide.
  • Animals in this group usually outnumber all other taxa in the marine zooplankton.


  • Drift in water column often hanging motionless.
  • Locomotion by slowly sinking or by swimming smoothly in circles or spirals by rapidly vibrating the second antennae.
  • Can respond to danger quickly by upward darting jumps carried out by the thoracopods.
  • Many species have been observed to undergo diel vertical migration; feeding at the surface layers at night and migrating deeper during the day.
  • Mostly herbivores.
  • Suspension feeders; continuous feeding current created by head appendages.
  • Larval development metamorphic. Embryos carried in single or paired sacs. Eggs can also be deposited externally. Long, usually slender body.