Biological features of the icefish Champsocephalus gunnari from commercial catches in Subarea 48.3 during the period from 8 December 1999 until 31 January 2000

In the period from 11 December 1999 to 31 January 2000 Russian trawler "Zakhar Sorokin" carried out fishing the icefish Champsocephalus gunnari feeding consent rations in the western shelf of the South Georgia Island. Icefish 26-40 cm in length, with the average size of 30.3 cm made up the bulk of the catches. Length-frequency distribution was characterized by bimodality, with frequency peaks under 27-29 and 33 cm for fish aged 3 and 4 years. The by-catch of small size Champsocephalus gunnari (with the length of 24 cm and less) amounted to, on the average, 0.6% per a haul.
The male/female ratio, on the average, equalled to 1/1.2. The active process of gonad maturation, more rapid in females, was observed. In December gonad maturation stages II and II-III and in January - II-III and III, respectively, prevailed.
Icefish feeding intensity remained to be relatively high during all the period of observations. Mean stomach fullness amounted to 2.5. Antarctic krill Euphausia superba, the occurence of which in the stomachs was estimated at 86%, and Themisto gaudichaudii (27.8%), were the main feeding objects.
Mean prevalence and intensity of Champsocephalus gunnari infestation by leech Trulliobdella capitus was 11.9% and 1.3 and by parasitic copepods Eubrachiella antarctica - 37% and 3.