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Clausocalanus minor

Sewell (1929)

Download a fact sheet for Clausocalanus minor (PDF 410KB)


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


  • Female: 1.08 - 1.26 mm
  • Male: 0.79 - 1.04 mm

Distinguishing characteristics

  • Form of seminal receptacle, dorsal lobe conspicuous in lateral and ventral view and directed obliquely posteriad
  • Prosome : Urosome ratio


  • Longer ramus of P5 and genital pore on left side
  • Left P5 longer than urosome, armed distally with slender, straight setae
  • Right P5 2 or 3-segmented, distal segments usually large
  • Body and rostrum in lateral view similar to C. Farrani


  • Rostrum slender and curved ventroposteriad
  • Ventral profile of genital somite stepped posterior to genital pore
  • Terminal points of P5 segment 3 divergent and always spinulose on inner margins
  • Prosome:urosome ratio 2.64-3.07:1
  • Genital somite more than 1.5x as long as urosome somite 3
  • Dorsal lobe of seminal receptacle in lateral view conspicuous; a second lobe present anterior and medial to the dorsal lobe
  • Dorsal lobe of seminal receptacle in ventral view conspicuous and directed obliquely posteriad
  • Caudal rami as long as wide


  • Epipelagic, oceanic waters
  • Tropical
  • Confined to Indian and Pacific oceans


  • Generally herbivorous – omnivorous
  • Feeding strategy is to rapidly explore small volumes of water
  • Little known about ecology of this species


Boxshall, G. A. and S. H. Halsey (2004). "An introduction to copepod diversity." Ray Society Publications 166: i-xv, 1-966.

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

Razouls C., de Bovée F., Kouwenberg J. et Desreumaux N., 2005-2009. Diversity and Geographic Distribution of Marine Planktonic Copepods. Available at