Müller, 1906
Diagnosis
A large species with sculptured pattern of rectangular cells covering carapace. Each rostrum drawn out into a pointed process which is longer on the left (C. ametra Habitus 2, C. ametra Habitus 4). Postero-dorsal corner with spines on both valves, again left corner spine longer than right. Carapace produced into small processes at posteroventral corners. Male first antenna "e" seta with armature of 35-40 long flanged spines (C. ametra 4). Hook appendage on the left second antennal endopodite forms a right-angle, whereas the right is strongly re-curved (C. ametra 5). Red when alive. A characteristic species.
Remarks
The only species that might be confused with C. ametra is C. imbricata (Conchoecia imbricata). They are readily distinguished on size, the longer and more symmetrical rostral processes and the longer process at the postero-ventral corner in C. imbricata. It was placed in the imbricata group by Müller, 1906. Poulsen, 1973 attributed it to Claus' genus Conchoecissa.
Distribution
Widely distributed in all the major oceans. Its poleward limit 62°N 44°S seems to be related to the polar fronts in the various oceans. Its bathymetric range is 700-1500m in the North Atlantic i.e., deep mesopelagic/shallow bathypelagic. 1, 2, 3, 4 (R.R.S. Discovery Map).
Type specimens
None designated, status of original material uncertain.
Type locality
Original description based on material from several Atlantic and Indian Ocean stations between 31°N and 37°S.