Attributes / relations provided by
♦ ¹CephBase - Cephalopod (Octopus, Squid, Cuttlefish and Nautilus) Database
♦ ²McMeans, Bailey C., et al. "The role of Greenland sharks (Somniosus microcephalus) in an Arctic ecosystem: assessed via stable isotopes and fatty acids." Marine Biology 160.5 (2013): 1223+. Academic OneFile. Web. 14 July 2014.
♦ ³Estimated Fish Consumption by Hooded Seals (Cystophora cristata), in the Gulf of St. Lawrence, M. O. Hammill, C. Lydersen, K. M. Kovacs and B. Sjare, J. Northw. Atl. Fish. Sci., Vol. 22: 249–257 (1997)