Age and growth of Antarctic Euphausiacea (Crustacea) under natural conditions

Five species of Antarctic euphausiid crustaceans were studied from the Antarctic Peninsula and the southeastern Weddell Sea.
Life spans range from two years for Euphausia frigida to six years for the krill Euphausia superba. Growth in length and weight was calculated by non-linear regressions. No difference in growth of krill were observed between the Antarctic Peninsula area and the eastern Weddell Sea. Former opinions that differ are discussed. Seasonal growth was re-analyzed for the species Euphausia triacantha, and a three-year life span proposed. Male Euphausia crystallorophias have a shorter life span than females, while their growth rate is similar. A short description of the life cycle and generation time of each species is given. In general, Antarctic euphausiids seem to remature and spawn at least twice and in some cases three times during their life, except for E. frigida which spawns only once.