Baird, 1850
Species of cypridinids are readily recognised in having eyes, either compound (Macrocypridina) or naupliar (Gigantocypris). Adult females that are >2 mm in length and are carrying embryos within the dorsal posterior region of the carapace are immediately attributable to being cypridinids. When sampling inshore, species not described here may be encountered.
Adult Macrocypridina are immediately identifiable because of their chocolate-brown coloration that persists after long periods of preservation. There are two mesopelagic species,
¥ Macrocypridina castanea Brady 1897 (Macrocypridina castanea) and
¥ Macrocypridina poulseni Martens 1979 (Macrocypridina poulseni ) distinguished by the shapes of their carapaces: the latter species was originally designated Macrocypridina castanea var. rotunda by Poulsen (1962).
The two Gigantocypris species are also immediately recognisable by their large size and rotundity.
¥ Gigantocypris dracontovalis Cannon 1940 (Gigantocypris dracontovalis) is either abyssopelagic or benthopelagic which is smaller than the more abundant bathypelagic species
¥ Gigantocypris muelleri Skogsberg 1920 (Gigantocypris muelleri), and the ventral gape of the carapace extends its full length. The setation around the rostrum is also distinctive. Very large colourless specimens occur occasionally in very deep water and probably belong to a third species. In the North Atlantic Gigantocypris muelleri is somewhat smaller than specimens collected in the Southern Ocean, but where their size changes and if this is of taxonomic significance needs to be determined.
Species information:
Cypridinidae.pct