Deep-Water Crustacea of the Genus Sergestes (Decapoda, Natantia) from Cook Strait, New Zealand
Four species, namely Sergestes arcticus, S. cf. S. seminudus, S. potens and S. japonicus, are recorded and described. Of these, S. japonicus is recorded for the first time from the Southern Hemisphere. S. cf. S. seminudus and S potens are also new to the New Zealand fauna, whilst S. arcticus has previously been recorded in the area only as a larval stage.
S. potens and S. japonicus are uniform scarlet species without internal luminescent organs (organs of Pesta) and are referred to the subgenus Sergio, here formally defined. Sergestes arcticus and S. cf. S. seminudus are particoloured red and transparent species which possess organs of Pesta and are referred to the subgenus Sergestes s.s. here formally defined. A synopsis of the 57 species recognized in the genus is given.
S. arcticus is abundant at about 100 fathoms during the night in Cook Strait, but probably sinks into deeper water during the day; the partially benthic S. potens is recorded from groper and ling stomachs caught in 40 to 60 fathoms. All records of Sergestidae from the New Zealand region are discussed, and a checklist of the recognized species given.