Chemical composition of the flesh and other tissues of antarctic fish species of the families channichthyidae and nototheniidae

Abstract

The muscle, intestinal tract, stomach, spleen, heart, pyloric caeca, gonads and liver of four Antarctic fish species, Notothenia neglecta, Notothenia gibberifrons, Chaenocephalus aceratus and Champsocephalus gunnari, were analysed for moisture, crude protein, carbohydrate, fat, ash, chloride and phosphorus. The chemical composition of the flesh of the fish showed that all four species are valuable food fishes with a high protein (17–19%) and a low to moderate fat content (0·8–1·9%). In all fishes investigated high amounts of trimethylamine oxide-nitrogen were present. Levels of trimethylamine-nitrogen were substantially higher (5 mg/100 g) and that of dimethylamine-nitrogen lower (0·05 mg/100 g) than in North Atlantic fish, while the ammonia-nitrogen content was comparable (10 mg/100 g). During distillation only nototheniids underwent deamination reactions leading to high TVB-N values, ice-fishes were unaffected. N. neglecta and N. gibberifrons were found to store considerable amounts of carbohydrates and fat in their livers (4·6% and 8·2% carbohydrates and 16·3% and 14·4% fat, respectively), Ch. gunnari accumulates fat in intestinal tract, spleen and pyloric caeca. The stomachs of all fishes had high chloride levels. The livers of Chaenocephalus aceratus were heavily infested (up to 20 wt%) by the parasitic nematode Contracaecum spec.