Antarctic krill, Euphausia superba Dana, demography studies in the seas of Sodruzhestvo and Cosmonauts (Indian Ocean sector of Antarctica)

The materials on Euphausia superba biological state and size composition in the Indian Antarctic seas for the period from 1985 to 1990 are analyzed to form an opinion about its growth, life duration, as well as about the interannual variability in the above parameters.
According to our data, duration of E.superba life cycle somewhat exceeds 5 years in the Sea of Cosmonauts and 6 years in the Sea of Sodruzhestvo. E.superba growth rate ranges from 0.126- 0.133 mm per day in the first year 0f life to 0.028-0.041 mm per day in the fifth year under condition that E.superba grows 180 days per year.
Bertalanffy growth curves calculated for different areas are close to that obtained by Australian researchers (Hosie et al., 1988) for the Prydz Bay by data for 1981-1985.
Basing on long-term observations, relations are noted between E.superba age composition and its spawning efficiency in coastal areas of the Seas of Sodruzhestvo and Cosmonauts. The presence of relatively independent (self-reproducing) groupings of E.superba is assumed in these areas.