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Paracalanus indicus

Wolfenden, 1905

Download a factsheet for Paracalanus indicus (PDF 485KB)


Phylum Arthropoda
Subphylum Crustacea
Class Maxillopoda
Subclass Copepoda
Order Calanoida
Family Paracalanidae
Genus Paracalanus
Species indicus


  • Male: 0.85-1.02 mm.
  • Female: 0.85-0.95 mm.

Distinguishing characteristics

  • Small oval copepods
  • Cephalosome fused with first pedigerous somite
  • A1 extends beyond prosome
  • Rostrum composed of 2 fine filaments
  • Posterior prosome segments rounded
  • Exopodites of P3 and P4 with serrated outside margin
  • P4 exopod segment 3 with a spine which is closer to the end of the segment than the start
  • Small P5, which is slender, short, uniramous, symmetrical and 2-segmented
  • Genital somite and caudal rami symmetrical


  • A1 extends to about the distal border of urosome somite 2
  • P5 uniramous, asymmetrical, with 5 segments on left and 2 on right. P5 extends beyond posterior border of urosome somite 3, right leg extends beyond distal border of left leg segment 2
  • Anal somite longer than urosome somite 4
  • Caudal rami 2x as long as wide


  • Urosome 4-segmented
  • Short genital somite
  • P5 distal segment cylindrical , terminal spine longer than its joint, outer distal spine short, about ¼ length of terminal segment
  • Genital somite widest anteriorly in dorsal view
  • Caudal rami 2x as long as wide with short inner seta
  • A1 extends just beyond the anal somite, all segments separate

(Boltovskoy 1999, Taw 1978)


  • Epipelagic
  • Coastal
  • Widespread in tropical and subtropical waters of the Atlantic, Pacific and Indian Oceans, also found in subantarctic waters
  • Common in coastal waters around Australia including Tasmania


  • Suspension feeders

  • Common prey for planktivorous fish in shallow estuaries

  • Not tolerant of high particulate loads found in shallow estuaries

  • One of several neritic species that are commonly parasitized by protists

  • Suspension feeders that cannot tolerate the high particulate loads found in some shallow estuaries, and in those cases are often out-competed by Acartia tranteri.

  • Predation rate on Paracalnus indicus by small planktivorous fish is approximately twice that of Acartia tranteri, especially in shallow waters where seagrass beds are prominent.

  • Appears that Paracalanus indicus has greater visibility and lesser ability to avoid capture than Acartia tranteri (Kimmerer and McKinnon 1987).


Bradford-Grieve, J. M. and Markhaseva, E.L.(1999) Copepoda. South Atlantic Zooplankton. D. Boltovskoy. Leiden, The Netherlands. Backhuys Publishers.1: 869-1098.

Bradford-Grieve, J. M. (1994) The marine fauna of New Zealand: Pelagic Copepoda: Megacalanidae, Calanidae, Paracalanidae, Mecynoceridae, Eucalanidae, Spinocalanidae, Clausocalanidae. National Institute of Water and Atmospheric Research. Wellington, New Zealand.

Conway DVP, White, R.G., Hugues-Dit-Ciles, J., Gallienne, C.P. and Robins, D.B. (2003) Guide to the coastal and surface zooplankton of the south-western Indian Ocean, Vol Occasional Publications No. 15. Marine Biological Association of the United Kingdom.

Kimmerer, W.J. and McKinnon, A.D. (1990) High mortality in a copepod population caused by a parasitic dinoflagellate. Marine Biology 107: 449-452.

Taw, N. (1978) Some common components of the zooplankton of the southeastern coastal waters of Tasmania. Papers and Proceedings of the Royal Society of Tasmania 112: 69-136.