Size-related dietary changes observed in the squid Moroteuthis ingens at the Falkland Islands: stomach contents and fatty-acid analyses

• Published in: Polar Biology
• Main Authors: Phillips, Katrina L., Nichols, Peter D., Jackson, George D.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer 2003
• Subjects: Polar Biology
• Online Access: https://oceanrep.geomar.de/id/eprint/53390/; https://oceanrep.geomar.de/id/eprint/53390/1/4088.pdf; https://doi.org/10.1007/s00300-003-0509-9

Dietary composition of the onychoteuthid squid Moroteuthis ingens at the Falkland Islands was related to predator size, as shown by stomach contents and fatty-acid analyses. Comparisons were made between two size classes of squid: those of mantle length <200 mm and those of mantle length >200 mm. Smaller squid had frequently consumed crustaceans and cephalopods; fish were of secondary importance. Larger squid consumed mostly fish and moderate amounts of cephalopods, but had rarely consumed crustaceans. These findings were supported by comparisons drawn between digestive-gland fatty-acid profiles and the fatty-acid profiles of potential prey species. Fatty-acid analyses indicated that the crustaceans Euphausia lucens, Munida gregaria and Themisto gaudichaudii were important prey items of smaller squid, whereas stomach content and fatty-acid analyses indicated that Gymnoscopelus nicholsi of around 100 mm standard length represented much of the fish prey of larger squid.