Aegisthus mucronatus

Taxon-Order: 
Harpacticoida

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Distribution: 
Off Southern California; Cape Mendocino, CA; Strait of Juan De Fuca, WA; South Africa, near Tristan da Cunha Id.; near Cape Verde Id.; Bay of Biscay; Gulf of Gascogne; Atlantic slope off Ireland; Gulf of Maine.
Habitat: 
Mesopelagic to bathypelagic, shelf and shelf break.
Size: 
Female 2.2-2.6 mm; male 1.7-2.0 mm
Useful Facts or Characters: 

In the both sexes the caudal setae are about 4-6 times the length of the cephalothorax with a bifid end.  The 1st antennae are 6-segmented in females and 7-segmented in males.  The males lack the long rostrum that is prominent in females.

Natural History: 

Elongate, bifid caudal setae.

References: 

http://www.marinespecies.org/copepoda/aphia.php?p=taxdetails&id=115509

http://copepodes.obs-banyuls.fr/en/fichesp.php?sp=1823

Davis, C.C. (1949)  The pelagic Copepoda of the northeastern Pacific Ocean.  University of Washington Publications in Biology 14: 1-118.

Johnson, M.W.  (1937)  Notes on the final metamorphosis of the male of Aegisthus mucronatus Giesbrecht, and its bearing on the status of some uncertain species.  Trans. Amer. Micr. Soc. 56: 505-509.