Distribution and biological characteristics of two toothfish species of genus Dissostichus (family Nototheniidae) off Bouvet Island

In 2010, two toothfish species, Patagonian (D. eliginoides) and Antarctic (D.mawsoni) toothfish, were registered during the fishery on Dissosyichus spp. on the shelf edge and slope of Bouvet Island. Their commercial concentrations were found also on the neighboring underwater plateaus surrounding the island. The vertical distribution of two species was differentiated distinctly, with the crossover point at depth of 1300 m. For both species the size and weight compositions were studied; indices of stomach fullness and qualitative diet composition as well as maturation stages of gonads and their weight were determined; gonadosomatic indices (GSI) were calculated. The sex ratio in catches and vertical distribution of toothfish in the fishing area were analyzed also.