Feeding of the Antarctic Krill Euphausia Superba

Abstract

ABSTRACT Measurements of rates of feeding indicate that Euphausia superba can feed on particles ranging from nanophytoplankton to macrozooplankton; a typical animal of 120 mg dry weight processes about 450 ml water per h and ingests at a maximum about 10% of its body carbon per day. A food concentration of about 100 µg carbon 1–1 allows the animal to ingest its minimum food requirement of 2.3% body carbon per day. Measurements of 210Po and 210Pb indicate krill from Bransfield Strait in February 1982 were feeding herbivorously. Photographic analysis of the thoracic legs employed by E. superba for feeding indicates that the mechanical power required to extract phytoplankton from the water ranges up to about 30% of its total respiratory energy.