Feeding habits of the ommastrephid squid Nototodarus sloanii on the Chatham Rise, New Zealand

Abstract

The diet of the squid Nototodarus sloanii was determined from examination of stomach contents of 388 specimens of 14.3–41.0 cm dorsal mantle length sampled at depths of 211–760 m on the Chatham Rise, New Zealand. Prey items were predominantly mesopelagic fishes, with some crustaceans and cephalopods. The most important prey species identified was Maurolicus australis, followed by Lampanyctodes hectoris, and unidentified squids (Teuthoidea). Multivariate analyses using distance‐based linear models, non‐parametric multi‐dimensional scaling, analysis of similarities, and similarity percentages, indicated crustaceans were more important in the diet of smaller squid (83–480 g), the fish component of the diet was dominated by L. hectoris on the east Chatham Rise and M. australis on the west Chatham Rise, and there may be a difference in diet with sex, with crustaceans and cephalopods more important for females. The results indicated that N. sloanii, similar to other ommastrephid squids, foraged primarily in the mesopelagic layers.

Keywords:

• diet
• trophic relationships
• variability
• mesopelagic