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Clausocalanus parapergens

Frost & Fleminger (1968)

Download an fact sheet for Clausocalanus parapergens (PDF 475KB)


Phylum Arthropoda
Subphylum Crustacea
Class Maxillopoda
Subclass Copepoda
Order Calanoida
Family Clausocalanidae
Genus Clausocalanus
Species parapergens


  • Female: 0.97 - 1.38 mm
  • Male: 0.97 - 1.14 mm

Distinguishing characteristics

  • Form of seminal receptacle
  • Shape of forehead and rostrum
  • Prosome : Urosome ratio
  • Female is similar to C.brevipes, the body and structure of the seminal receptacle is the same but C. parapergens urosome is relatively shorter
  • Male similar to C.arcuicornis


  • Rostrum knob like, protrudes ventrally (lateral view)
  • Longer ramus of P5 and genital pore on left side
  • Left P5 longer than urosome, often slender in lateral view
  • Right P5 2-3 segmented, distal segments reduced in size
  • Caudal ramus <1.6 times as long as wide


  • A1 segment 2 less than 1.4 times as long as segment 4
  • Rostrum short, thick and curved ventroposteriorly (lateral view)
  • Posterior margin of female prosome angular in lateral view
  • P5 segment 3 more than twice as long as segment 1
  • 3rd segment of P5 more than 2 times as long as 1st segment of P5
  • Prosome:urosome ratio 3.10-3.61:1
  • Ventral profile of genital somite in lateral view somewhat undulant
  • Genital somite more than 1.5 times as long as urosome somite 3
  • Ventral lobe of seminal receptacle in lateral view large, visible anterior to base of dorsal lobe
  • Seminal receptacle dorsal lobe bulb shaped, constricted in attachment to ventral lobe


  • Tropical-subtropical, circumglobal



  • 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.
  • Frost B, Fleminger A (1968). A revision of the genus Clausocalanus (Copepoda: Calanoida) with remarks on distributional patterns in diagnostic characters. Bulletin of Scripps Institution of Oceanography 12:1-235
  • Taw 1978, pp 90