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Oncaea scottodicarloi

Heron & Bradford-Grieve (1995)

Download a fact sheet for Oncaea scottodicarloi (PDF 371KB)


Phylum Arthropoda
Subphylum Crustacea
Class Maxillopoda
Subclass Copepoda
Order Poecilostomatoidae
Family Oncaeidae
Genus Oncaea
Species scottodicarloi


  • Female: 0.48 - 0.61 mm
  • Male: 0.41 - 0.48 mm

Distinguishing characteristics

  • Size
  • Proportional lengths of urosome somites
  • Form and location of sclerotization between genital apertures


  • Prosome 2.5 times length of urosome (excluding caudal rami), 2.2 times urosome length (including caudal rami)
  • Caudal rami about 1.6 times longer than wide (shorter than female)


  • Exoskeleton moderately chitinized
  • Prosome 2.8 times length of urosome (excluding caudal rami) 2.4 times urosome length including caudal rami
  • Genital double-somite 1.5 times as long as maximum width & 2.5 times as long as postgenital somites combined; almost square-shaped genital somite, stockier & broader
  • Straight sclerozitation between genital apertures
  • Anal somite 1.8 times wider than long & about ¾ length of caudal rami
  • Caudal ramus about 2.3 times as long as wide


  • Closely related to O. media, O. waldermari and O. curta
  • Distinguish between female O. media by proportional lengths of urosome somites (more elongated genital somite in O. media-genital somite is 2 times as long as the rest of urosome)
  • Form and location of sclerotization between genital apertures (in genital openings are closer to top 1/3 from the top while in O. scottodicarloi genital openings are almost ½ way from the top of genital somite)
  • Relative lengths of endopod spines of P4




  • 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.