The diet of antarctic squid: comparison of conventional and serological gut contents analyses

The alimentary tracts of 12 species of Antarctic squid were examined visually and serologically for the presence of Euphausia superba. Only four species, Alluroteuthis antarcticus, Galiteuthis glacialis, Martialia hyadesi and Psychroteuthis glacialis, contained material which was identifiable to species visually. Myctophid fish and euphausiids were the most common prey item. Serology showed that specimens of six species had eaten euphausiids. Where antisera showed cross-reactions with other potential prey species, biogeographical and haul data was used to determine the species of Euphausia consumed. P. glacialis (n=19) had consumed E. superba. Mastigoteuthis psychrophila (n=10) had eaten E. superba and/or E. triacantha. Brachioteuthis picta (n=6), M. hyadesi (n=27), and two Moroteuthis spp. (n=2) had consumed unidentified euphausiids. Bathyteuthis abyssicola (n=13) and Histioteuthis eltaninae (n=13) had not preyed on euphausiids. B. picta appeared to have fed in the net