On oceanic features, toothfish fed mainly on Macrourus spp. Diet varied significantly with toothfish size and location on northern parts of the Mawson and Iselin banks of … The dietary composition of the Antarctic toothfish, clas- sified into two size classes (Class I, 104–140 cm; Class II, 140–176 cm), did not significantly differ between the groups (χ2= 1.800, df= 4, p> 0.05). Diet of Antarctic toothfish (Dissostichus mawsoni) from the continental slope and oceanic features of the Ross Sea region, Antarctica DARREN W. STEVENS1, MATTHEW R. … Rattails are doubly important as they are also a favourite food for toothfish. In this paper we assess relative weight given to direct, observational evidence of prey taken, as opposed to indirect evidence from scat and biochemical analysis, and conclude that toothfish are important to Weddell seals ( Leptonychotes weddellii ). Uncertainty exists over the importance of Antarctic toothfish (Dissostichus mawsoni) as prey of top predators in the Ross Sea.
Overall, the diet of sub-adult toothfish was similar to that of adult toothfish, with a dominance of piscivory on benthic fishes and cephalopods, augmented by benthic invertebrates.
Monitoring rattail abundance is a key objective of the Ross Sea Research and Monitoring Plan. This indicated that fish were the dominant prey item, comprising 84.5% for Class I and 90.5% for Class II of the weight of the diet.
Medium‐size toothfish (40–60 cm LT) fed on the same prey, but the number of prey items increased to 1–2 items per fish. but also fed on Antimora rostrata, cephalopods and the occasional mesopelagic to epipelagic fish. Large toothfish (>60 cm LT) switched their diet to other large pelagic fishes occurring near the bottom (Macruronus magellanicusand Micromesistius australis australis), again taking mostly one prey item at a time. Another important bycatch species of the toothfish fishery is the rattail (or grenadier if you are in the fish marketing business). The diet of Antarctic toothfish (Dissostichus mawsoni) in the Ross Sea region was examined based on stomach samples obtained from observers on New Zealand fishing vessels in 2003 and 2010.