The developmental rate of Euphausia crystallorophias larvae in Ellis Fjord, Vestfold Hills, Antarctica

Abstract

Euphausia crystallorophias is the dominant Zooplankton species in the neritic seas of Antarctica, where it occurs in similar abundances to those ofEuphausia superba in more offshore areas. Despite its great abundance and probable ecological significance, few details are known of this species' development, life history and ecology. This study found thatE. crystallorophias spawned in Ellis Fjord from late November to early December and completed its larval development under the sea ice during the Antarctic winter. The mean time forE. crystallorophias eggs to develop to furcilia stage VI was 235.5 days, which is virtually identical to the developmental time already reported in the laboratory, but almost twice that ofE. superba. This slow development rate is likely to be due either to the low water temperatures (<0°C) in whichE. crystallorophias lives, or to low levels of food being available over winter.