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Clausocalanus paululus

Farran (1926)

Download a fact sheet for Clausocalanus paululus (PDF 343KB)


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


  • Female: 0.65 - 0.86 mm
  • Male: 0.47 - 0.56 mm

Distinguishing characteristics

  • Form of seminal receptacle - often inconspicuous in lateral or ventral view
  • Prosome : Urosome ratio
  • Shape of forehead and rostrum


  • Body short and stocky
  • Rostrum in lateral view knob-like and protruding ventrally
  • Longer ramus of P5 and genital pore on left side
  • Left P5 longer than urosome, right P5 2 segmented, distal segment small


  • Body robust
  • Rostrum in lateral view slender curved ventroposteriad
  • Terminal points of P5 segment 3 not divergent and may have spinules on inner and outer margins
  • Prosome:urosome ratio 2.59-3.00:1
  • Ventral profile of genital somite in lateral view with a step posterior to the genital pores
  • Genital somite more than 1.5 times as long as urosome somite 3
  • Seminal receptacle often inconspicuous in lateral or ventral view
  • Dorsal lobe of seminal receptacle not well separated from ventral lobe in lateral view, but well demarcated in ventral view


  • Epipelagic
  • Subtropical, circumglobal
  • Coastal, offshore


  • Generally herbivorous – omnivorous
  • Feeding strategy is to rapidly explore small volumes of water
  • Female can carry 2 spermatophores
  • Multiple generations (up to 5) per year


  • 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
  • Shmeleva & Kovalev (1974)