University of Tasmania, Australia

UTAS Home | UTAS Staff | UTAS Contacts


UTAS Home > IMAS Home > Image Key > Copepoda > Cyclopoida > Oncaeidae >  Oncaea clevei

Oncaea clevei

Früchtl (1923)

Download a fact sheet for Oncaea clevei (PDF 412KB)


Phylum Arthropoda
Subphylum Crustacea
Class Maxillopoda
Subclass Copepoda
Order Poecilostomatoida
Family Oncaeidae
Genus Oncaea
Species clevei


  • Female: 0.62 - 0.68 mm
  • Male: 0.49 - 0.57 mm

Distinguishing characteristics

  • P2 bearing somite with dorso-posterior projection in lateral view
  • Very similar to O.paraclevei, can be distinguished by location of genital apertures & form of sclerotization


  • Prosome 2.5 times the length of urosome, excluding caudal rami, 2.2 times urosome length, including caudal rami
  • Caudal rami about 1.8 times longer than wide, shorter than female


  • Exoskeleton well chitinized
  • Prosome 2.4 times length of urosome excluding caudal rami, 2.1 times urosome length including caudal rami
  • P2 bearing somite with dorso-posterior projection in lateral view (variable in conspicuousness)
  • Integumental pores on prosome
  • Pleural areas of P4 bearing somite elongate and with rounded posterolateral corners
  • Genital double-somite rectangular in dorsal aspect, 1.4 times as long as maximum width & 1.6 times as long as postgenital somites combined, largest width measured near anterior margin,lateral margins of genital double-somite rounded at anterior quarter, posterior part tapering slightly
  • Paired genital apertures located very close to dorso lateral margin at about 2/5 the distance from anterior margin of genital double-somite, armature represented by 1 spine and 2 minute spinous processes
  • Sickle-shaped sclerotiziation between, but slightly posterior to genital apertures
  • Anal somite 1.4 times wider than long,slightly shorter than caudal rami
  • Caudal ramus about 2.3 times as long as wide




  • Heron, G. A. and J. M. Bradford-Grieve (1995). "The marine faunaof New Zealand: Pelagic Copepoda: Poecilostomatoida: Oncaeidae." New Zealand Oceanographic Institute Memoir 104.
  • Bottger-Schnack, R. (2001). "Taxonomy of Oncaeidae (Copepoda, Poecilostomatoida) from the Red Sea. II. Seven species of Oncaea s.str." Bulletin of Natural History Museum 67(1): 25-84.