Key character
Species with long c or d setae on the antennal endopodite. Three species of the genus occur in the South Atlantic. The first two have small but distinct spines at the posterior dorsal corner of the carapace valves, and are readily distinguished by their different colouring when live. The limb structure is very similar between all three species.
¥ Orthoconchoecia secernenda (Vavra, 1906) (Orthoconchoecia secernenda, Orthoconchoecia secernenda 2) with small but distinct spines at the posterior dorsal corner of the carapace valves. Rather opaque, larger and more intensely coloured than the next species. Juveniles of O. secernenda have much larger shoulder vaults and even in the adults the vaults tend to be more powerfully developed, also compared to the next species.
¥ Orthoconchoecia bispinosa (Claus, 1890) (Orthoconchoecia bispinosa, Orthoconchoecia bispinosa 2) also with small but distinct spines at the posterior dorsal corner of the carapace valves. Translucent paler-coloured, smaller than the previous species
¥ Orthoconchoecia haddoni (Brady and Norman, 1896) (Orthoconchoecia haddoni, Orthoconchoecia haddoni 2) lacks the spines at the posterior dorsal corner and shows a large sexual disparity in size, the females being much larger. There are two races of O. haddoni, with the large form occurring at high latitudes and a smaller form at low latitudes where it is often associated with upwelling regions.
Species information:
Genus Orthoconchoecia.pct