Adult Antarctic Krill Feeding at Abyssal Depths

摘要: Antarctic krill (Euphausia superba) is a large euphausiid, widely distributed within the Southern Ocean [1], and key species in food web [2]. The Discovery Investigations early 20(th) century, coupled with subsequent work both nets echosounders, indicated that bulk of population postlarval typically confined to top 150 m water column [1, 3, 4]. Here, we report for first time existence significant numbers feeding actively at abyssal depths Ocean. Biological observations from deep-water remotely operated vehicle Isis austral summer 2006/07 have revealed presence adult superba Dana), including gravid females, unprecedented Marguerite Bay, western Peninsula. Adult were found close seabed all but absent fjords inshore. At locations where detected they seen be feeding, many there exuviae (cast molts). These revise significantly our understanding depth distribution ecology krill, central organism ecosystem.