University of Tasmania, Australia

UTAS Home | UTAS Staff | UTAS Contacts


UTAS Home > IMAS Home > Image Key > Copepoda > Calanoida > Rhincalanidae >  Rhincalanus gigas

Rhincalanus gigas

Brady (1883)

Download a fact sheet for Rhincalanus gigas (PDF 299KB)


Phylum Arthropoda
Subphylum Crustacea
Class Maxillopoda
Subclass Copepoda
Order Calanoida
Family Rhincalanidae
Genus Rhincalanus
Species gigas


  • Female: 6.46 - 9.30mm
  • Male: 6.90 - 7.20mm

Distinguishing characteristics

  • Large size


  • Right P5 terminal exopod spine extends almost as far as distal end of endopod, both rami with many spinules.
  • Left P5 terminal spine extends almost as far as right leg, segment 2 with inner border of spinules and outer distal spines
  • Size is diagnostic
  • Very few males have been found, P5 very similar to R. nasutus, check for spines on left P5 segment 2


  • Very large, distinct body and head shape
  • Pointed cephalosome bearing bifid rostrum
  • A1 at least 1.5x length of body
  • 5th thoracic somite, and sometimes somite 3, with dorsal spines on posterior margins
  • 4th and usually 3rd thoracic somites with no spines
  • Urosome only short (~15% of body length)




  • Bradford-Grieve J., (1994). The marine fauna of New Zealand: Pelagic calanoid copopoda: Megacalanidae, Calanidae, Paracalanidae, Mecynoceridae, Eucalanidae, Spinocalanidae, Clausocalanidae. New Zealand Oceanographic Memoir 102.
  • Bradford-Grieve, J. M., E. L. Markhaseva, et al. (1999). Copepoda. South Atlantic Zooplankton. D. Boltovskoy. Leiden, The Netherlands, Backhuys Publishers. 1: 869-1098.
  • Guglielmo, L., Ianora, A. editors. (1995) Atlas of marine zooplankton. Straits of Magellan. Copepods. xiv, 279p. Berlin: Springer Verlag, 1995