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Delibus nudus

Delibus nudus (Sewell, 1929)

Download a fact sheet for Delibus nudus (PDF 628KB)


Phylum Arthropoda
Subphylum Crustacea
Class Maxillopoda
Subclass Copepoda
Order Calanoida
Family Paracalanidae
Genus Delibus
Species nudus


  • Female: 0.4-0.7 mm
  • Male: 0.42-0.52 mm

Distinguishing characteristics

  • Very small, less than 1 mm
  • Cephalosome and 1st pedigerous somite are fused; somites 4 and 5 also fused
  • A1 extends to posterior border of prosome
  • Rostrum bifurcate, branches short and wide
  • Basis of P1 with inner edge setae
  • P2-4, outer edge of exopod segments 2-3 are smooth
  • P5 is reduced, only left P5 present, 2 segments in female, 5 in male
  • Female urosome 4-segmented, male 5-segmented


  • Urosome 5 segmented
  • P5 long, almost reaches to end of urosome


  • P5 short and ‘dagger’ like


  • Epipelagic
  • Oceanic, widespread in Atlantic, Indian and Pacific Oceans


  • Nothing appears to be known about the ecology of this species


  • 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.
  • Corral Estrada, J., (1970) in Thesis Doct., Univ. Madrid, A-129, Sec. Biologicas.
  • Razouls C., de Bovée F., Kouwenberg J. et Desreumaux N., 2005-2012. - Diversity and Geographic Distribution of Marine Planktonic Copepods. Available at