Ryocalanus antarcticus sp. nov. (Crustacea: Copepoda) – first ryocalanoid from the Southern Ocean

J. Renz, E.L. Markhaseva and K. Schulz

Proceedings of the Zoological Institute RAS, 2012, 316(2): 148–158 · https://doi.org/10.31610/trudyzin/2012.316.2.148

Full text

Abstract

A new ryocalanoid copepod, Ryocalanus antarcticus sp. nov., is described from both genders collected during the German expeditions EASIZ-II in 1998 and ANDEEP SYSTCO in 2008 above the seabed in deep waters of the Southern Ocean. The new species is well distinguished from congeners in the shape of the genital double-somite and the posterior corners of prosome, the structure of distal segments of geniculated antennule in male and details of leg 1 and limb armament. Species of Ryocalanus are separated into two groups. Group I contains medium to large sized copepods with a single rostrum, a geniculated moderately modified right antennule in the male, and the distal segments of the male uniramous leg 5 armed with terminal spines. Group II of Ryocalanidae share the small size (<1.6 mm), a bifid rostrum, the male highly complex geniculated right antennule, with strongly modified distal segments, and an indistinctly biramous male leg 5 with distal exopod segments lacking terminal spines. R. antarcticus sp. nov. is the first ryocalanoid copepod recorded from the Southern Ocean.

Key words

benthopelagic, Copepoda, Ryocalanus antarcticus sp. nov., Southern Ocean

Submitted May 10, 2012 · Accepted May 25, 2012 · Published June 25, 2012

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