Sars, 1902
Short Description:
Comantenna brevicornis is an aetideid calanoid copepod known after both sexes (female 1.70-2.60 mm and 1.2 mm male) from the northern part of the Atlantic Ocean, the Norwegian, Barents and North seas of the near-bottom localities.
Taxonomic Description:
Female. Total length 1.70-2.60 mm. Cephalothorax about 3 times longer than abdomen. Points of Th5 posterior corners sharpened, upturned and directed backwards (lateral view). A1 24-segmented, significantly shorter than cephalothorax. Re2 and Re3 A2 fused. Md, Mx2 typical of the genus. Mx1 gnathobase with 9 setae, second and third internal lobes with 2 and 3 setae respectively, protopodite near Ri base with 4 setae, Ri with 9, Re with 11 and external lobe with 6 setae. Mxp protopodite typical of the genus, Ri1 Mxp with 3 medial setae. External lobe on Ri P1 much better developed than in other species of genus. P1 with seta near Ri base.
Male. Total length 1.2 mm. Body robust, smoothly rounded in its anterior part and widest at the level of Th2, Th4 and Th5 fused. Points of Th5 posterior corners reduced to obtuse angles, and not directed backwards as in females. Abd2 slightly longer than Abd1, anal segment very short. A1 23-segmented, nearly as long as cephalothorax, in A1 proximal part there are many aesthetascs. A2 close to that in female, but 3 terminal setae on distal Re segment much better developed. Md gnathobase absent, Md palp base and its Re as in female; setae on Ri comparatively longer than that in female. Mx1 with reduced lobes, without setae and chewing spines, Ri comparatively well developed, with 8 setae. Mx2 reduced to small single lobe with 1 rudimentary spine. Mxp significantly weaker than in females, protopodite significantly thinner, without any setae, Ri1 also thin and with single seta, setae on last 5 segments of Ri comparatively longer than in female. P1-P4 as in female. P5 with 2-segmented protopodite. Left Ri 2-segmented, right Ri one-segmented; left Re 3-segmented, its last segment short; right Re 2-segmented, distal part of Re2 prolonged, curved in its terminal part and covered with thin hairs.
Vertical distribution:
Most probably benthopelagic species. Recorded at depths from 91 to 274 m near bottom (Sars, 1902).
Geographical distribution:
The Norwegian coast, the Barents Sea, the northern part of the North Sea, Irish waters, the north-eastern Atlantic (Sars, 1902; Vervoort, 1952).
Type locality: the Norwegian coast (Sars, 1902).
Material examined:
Species absent in the collections of the Zoological Institute, Russian Academy of Sciences, St. Petersburg; female and male from the collections of the Zoological Museum, Oslo University (Norway) were studied.