THE HISTOLOGICAL ANALYSIS OF OOGENESIS AND MATURITY OF ANTARCTIC TOOTHFISH FROM THE ROSS SEA

The results of the histological analysis of the Antarctic toothfish (Dissostichus mawsoni) reproductive system, caught in December - February 2005/2006 in the Ross Sea are presented. The morphological parameters, indices of gonads and condition by Fulton have been described. The histological criteria of the assessment of the ovary maturity stages, cytological parameters of oocytes and type of the toothfish oogenesis have been determined. At the maturing of toothfish, ovaries from the stages III to IV showed a slow increase in oocyte diameter. It was obtained that for Antarctic toothfish during the fishing period the individuals with gonads of the late III stage of maturity were dominated. Their ovaries contained two groups of vitellogenous oocytes. The large oocytes of the nearest spawning season with average diameter 2000 - 2200 ·10-6 m have composed 13.3% of total cell number.