Trophic ecology of the deep-sea squid Moroteuthopsis ingens (Cephalopoda: Onychoteuthidae) from the Chatham Rise, Aotearoa New Zealand

Cephalopods form important components of marine trophic systems worldwide, including those in the South Pacific. Moroteuthopsis ingens (Onychoteuthidae) is one of the most abundant deep–sea squids in the Aotearoa New Zealand region and is preyed upon by predators such as the sperm whale and orange roughy. However, despite the many publications on M. ingens’ diet, knowledge on its feeding ecology remains limited. In this study, we analysed the prey of M. ingens from the Chatham Rise (an ecologically and economically important region east of Te Waipounamu/New Zealand’s South Island) using DNA barcoding and otolith identification. Lanternfishes (Myctophidae) were the most frequently encountered prey item, but other teleost species, cephalopods and crustacean fragments were also found, indicating opportunistic and likely cannibalistic feeding behaviour. Five fish species (including a possibly undescribed species of Gymnoscopelus) and Bathyteuthis abyssicola are reported as prey items of M. ingens for the first time. Moroteuthopsis ingens appears to be a component of several dynamic food chains and likely plays an important role in the transfer of carbon throughout marine environments in the Southern Hemisphere.