Müller, 1906
Diagnosis
Carapace shape globular (C. acuticosta Habitus 1, C. acuticosta Habitus 3); typical of Müller's (Müller, 1906) curta group, and Claus' genus Mikroconchoecia (= Microconchoecia sensu Poulsen, 1973). Size >1mm with a concentric pattern of sculpturing and a secondary pattern of rectangles and polygons. The asymmetrical gland on the right valve opens at the postero-dorsal corner. The sensory setae on the first antenna of both sexes are bifid (C. acuticosta 1, C. acuticosta 3). Male first antenna "e" seta armature is a row of 12-14 small spines (C. acuticosta 4).
Remarks
This is one of the larger of the curta group of species. It is readily distinguished from the other large species in the group, C. stigmatica (Conchoecia stigmatica) by the position of the opening of the right asymmetrical gland, and the lack of anterior taper.
Distribution
In the North Atlantic, it is most abundant at higher latitudes at mesopelagic depths 200-500m. It also occurs in equatorial regions; this rather curious biogeographical distribution raises doubts as to whether all these records are conspecific. 1, 2, 3 (R.R.S. Discovery Map).
Type specimens
None designated; status of original material uncertain.
Type locality
Original material from between 4°N and 35°S in both Atlantic and Indian Oceans.