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Acartia (Odontacartia) pacifica

Steuer (1915)

Download a fact sheet for Acartia (Odontacartia) pacifica (PDF 529KB)


Phylum Arthropoda
Subphylum Crustacea
Class Maxillopoda
Subclass Copepoda
Order Calanoida
Family Acartiidae
Genus Acartia (Odontacartia)
Species pacifica


  • Female: 1.15 - 1.20 mm
  • Male: 1.12 mm

Distinguishing characteristics

  • Sharp points at end of prosome
  • Form of P5
  • Arrangement of spines on urosome


  • Spines on end of prosome
  • Inner edge setae of P5 left exopod long and with distinct hairs
  • Urosome somite 1 naked
  • Urosome somite 2 with a pair of spines
  • Urosome somite 3 with a pair of spines
  • Urosome somite 4 with a pair of smaller spines more towards midline
  • Anal segment with large hairs
  • Caudal rami with outer and inner edged hairs


  • Large spines on end of prosome, 2 smaller spines dorsally
  • P5 basis short, terminal spine with proximal knob and distal half bordered with hairs
  • Posterior border of genital somite with 2 small spines, urosome somite 2 with a pair of larger spines
  • Caudal rami with patches of hairs anterior to lateral setae


  • Epipelagic coastal and brackish waters
  • Pacific and Indian Oceans, not Atlantic


  • Resting eggs in sediments can be viable for up to 20 years
  • Exposure to heavy metals and pesticides in sediments can reduce recruitment from sediments to plankton
  • Can migrate horizontally to avoid UV-B harm


  • Bradford-Grieve, J. M., (1999) The marine fauna of New Zealand: pelagic calanoid copepoda: Bathypontiidae, Arietellidae, Augaptilidae, Heterorhabdidae, Lucicutiidae, Metridinidae, Phyllopodidae, Centropagidae, Pseudodiaptomidae, Temoridae, Candaciidae, Pontellidae, Sulcanidae, Acartiidae, Tortanidae. National INstitue of Water and Atmospheric Research, Wellington, New Zealand.
  • Greenwood, J. G. (1978). "Calanoid copepods of Moreton Bay (Queensland) 3. Families Temoridae to Tortanidae, excluding Pontellidae." Proceedings of the Royal Society of Queensland 89: 1-21.
  • Jiang et al. (2004)
  • Jiang et al. (2007)
  • Phukham N., 2008. - Species diversity of calanoid copepods in Thai waters, Andaman Sea. M.S. Sc. (Marine Science). Univ. Bangkok. 269 p.. (On line).
  • Razouls C., de Bovée F., Kouwenberg J. et Desreumaux N., 2005-2009. - Diversity and Geographic Distribution of Marine Planktonic Copepods. Available at
  • Tanaka O., 1965. - The pelagic copepods of the Izu region, Middle Japan. Systematik account XIII. Parapontellidae, Acartiidae and Tortanidae. Publs Seto mar. biol. Lab., 12 (5): 379-408.