Feeding patterns of nine species of Antarctic fish and assessment of their daily food consumption
Little is known about the feeding patterns of non-commercial fish species in Antarctic waters. The aim of this study is to collect information on the feeding patterns of several commercially non-targeted species in the Indian Ocean sector of the Southern Ocean: Nototheniidae (four species), Channichthyidae (three species) and Bathydraconidae (two species). The study concentrated on analysing the food composition of these species to find out their daily diet. One 36-hour station was carried out in the Kosmonavtov Sea (67°50'S; 41°24'E) in March 1988. All samples were taken from the depth range 300 to 350 m and a total of 1 165 stomachs were collected and analysed. The species studied were classified into the four following categories: (i) Chaenodraco wilsoni and Trematomus eulepidotus - planktivorous species with euphausiids, mainly Euphausia superba, being the staple food; (ii) Trematomus centronotus - a benthophage feeding mainly on amphipods, mobile and sedentary forms of polychaetes, with Euphausia superba also comprising a considerable portion of its diet; (iii) Trematomus hansoni - a euryphage; (iv) Dissostichus mawsoni, Cygnodraco mawsoni, Gymnodraco acuticeps, Chionodraco hamatus and Cryodraco antarcticus - predators feeding mainly on fish. The daily diet of these species was from 1 to 4% of their body weight. Annual food consumption by these species was calculated to be about five times their body weight.