Abstract:

Based on the samples collected from 4 austral summer sampling cruises from 1989/1990 to 1992/1993 in the Prydz Bay region,the Indian sector of the Southern Ocean,the number and development phase composition of ovarian oocytes in gravid females of Antarctic krill, Euphausia superba Dana,and the relations of the number of ovarian oocytes with body weight and body length were studied.The number of oocytes ranged from 2188 to 9263,with average of 5283.Year to year changes of the number of oocytes was not statistically significant.The relationship between the number of oocytes(OC) and body wet weight(WW,g) was OC=5172.1 WW-1121.6,R=0.856,that between OC and eye diameter(ED,mm)was OC=3799.1 ED-3175.6,R=0.431,and that between OC and uropod length(UL,mm) was OC=813.2UL-35.98,R=0.243.Four development phases of oocytes were found in gravid females,but their composition percentages varied with different samples which were collected in different times.It seemed that the complete maturity of almost all oocytes was an indication of egg laying.