Stomach contents of sub-adult Antarctic toothfish (Dissostichus mawsoni) from the western Ross Sea, Antarctica

The stomach contents of 190 sub-adult (51-100 cm TL) Antarctic toothfish (Dissostichus mawsoni) captured by bottom longline in the western Ross Sea were analysed. Fish were sampled during the 2005 fishing (Dec 2004 to Jun 2005) season and caught in 398-1678 m depths. Sub-adult D. mawsoni are primarily piscivorous, feeding on a wide variety of small to medium sized fish. Icefish (Channichthyidae) were the most important prey by frequency, weight and IRI, while small notothens (Nototheniidae) were more numerous. Whitson’s grenadier (Macrourus whitsoni), dragonfish (Bathydraconidae), and eel cods (Muraenolepididae) were also important. Glacial squid (Psychroteuthis glacialis) were found in about 20% of stomachs, but only 6% by IRI.
Samples were collected mainly from the continental slope along the northern edge of the Ross Sea. Although the study provides an important comparison of diet of adult and sub-adult fish collected from the same area, the results may not reflect the diet of the main part of the subadult population which is thought to reside on the main shelf to the south. It is therefore recommended that further stomach samples be collected from further south on the Ross Sea shelf.