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Clausocalanus jobei

Frost & Fleminger (1968)

Download a fact sheet for Clausocalanus jobei (PDF 308KB)


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


  • Female: 1.01 - 1.56 mm
  • Male: 0.87 - 1.07 mm

Distinguishing characteristics

  • Form of seminal receptacle
  • Shape of forehead and rostrum
  • Prosome : Urosome ratio
  • Female C. jobei is distinct from all other Clausocalanus spp. (except C. farrani) in having a ventral protuberance of the genital somite anterior to genital pores
  • C. jobei and C. farrani differ in form of rostrum in lateral view


  • Rostrum knoblike and protrudes ventrally
  • Prosome:Urosome ratio 2.29-2.60:1
  • Longer ramus of pereiopod 5 on left side, left pereiopod 5 longer than urosome, left pereiopod 5 armed distally with 2 thick curved spiniform setae
  • Right pereiopod 5 short, 2 segmented, 2nd segment very small


  • Rostrum long, slender and curved in lateral view
  • Posterior margin of female prosome rounded in lateral view
  • Prosome:Urosome ratio 2.32-2.92:1
  • Genital somite more than 1.5 times as long as urosome somite 3
  • There is a ventral protuberance of the genital somite anterior to genital pores


  • Tropical or sub-tropical distribution, circumglobal
  • Broadly neritic distribution throughout its range
  • Distribution distinct from C. farrani in the Indian & Pacific Oceans, areas of slight overlap found in western part of the eastern tropical Pacific Ocean


  • Carries eggs in a single, fragile sac
  • Herbivorous filter feeder


  • Bradford-Grieve, J. M., E. L. Markhaseva, et al. (1999). Copepoda. South Atlantic Zooplankton. D. Boltovskoy. Leiden, The Netherlands, Backhuys Publishers. 1: 869-1098.
  • Dakin, W. J. and Colefax A., (1940). "The plankton of the Australian coastal waters off New South Wales Part I." Publications of the University of Sydney: 210
  • 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
  • Saiz and Calbert, (1999)
  • Taw, N. (1978). "Some common components of the plankton of the southeastern coastal waters of Tasmania." Papers and proceedings of the Royal Society of Tasmania 112: 69-136.