Claus, 1890
Description
Instantly recognisable, because the postero-dorsal region of the carapace is developed into a long spinose pointed process [C.daphnoides-fem-lat; C.daphnoides-male-lat]. The rostra are developed into long curving processes particularly in the female [C.daphnoides-fem-vent]. Sculpture a clear reticulate pattern with strong longitudinal striae. The height/length ratio is 1/3 in males and 1/5 in females. Right asymmetrical gland opens just below the incisure on the anterior margin; the left opens just posterior to the hind end of the hinge.
Female, frontal organ undifferentiated, slightly enlarged ventrally, terminating in a down-turned point [C.daphnoides-1]. First antenna with finely hirsute dorsal seta.
Male, frontal organ capitulum only slightly down-turned with bluntly rounded end [C.daphnoides-3]. First antenna with short "a" and "c" setae; the "b" and "d" setae are 3/4's the length of the "e" seta, "e" seta armature 15-19 pairs of long pointed spines proximally more widely spaced [C.daphnoides-4].
Size
Female 5.2-5.90 mm, male 3.0-3.25 mm carapace length.
Depth range
Epipelagic to deep mesopelagic, but this extensive vertical range is the result of vertical migration.
Distribution in the North Sea
Northern North Sea
World distribution
Recorded from all oceans; 60°N-42°S in the Atlantic, where it may also occur >60°N according to Poulsen (1977).
Remarks
According to recent taxonomic revision, the species daphnoides is placed in the genus Conchoecilla (M.V. Angel, pers. com.). However, for technical reasons the former generic name Conchoecia had to be maintained in the multimedia files.
Müller (1906) described a form minor from the North Atlantic, with females 4.2-4.9 mm and males 2.25-2.45 mm in length. This may either be a seasonal variant or another sibling species. C. daphnoides undertakes extensive diel vertical migrations, has a marked seasonality in its breeding cycle at latitudes >40°.
[After Angel, 2000]