Biological characteristics of euphausiids preyed upon by Adelie penguin, Pygoscelis adeliae, breeding at Hukuro Cove, Lutzow-Holm bay in 1995/1996

• Main Authors: Endo,Yoshinari, Asari,Hiroshi, Watanuki,Yutaka
• Format: Report
• Language: English
• Published: Graduate School of Agricultural Science, Tohoku University/Graduate School of Agricultural Science, Tohoku University/Faculty of Agriculture, Hokkaido University 2000
• Subjects: Euphausia superba; Euphausia crystallorophias; Adelie penguin; biological sampler; Lutzow-Holm Bay; Polar bioscience; Pygoscelis adeliae; Sea ice
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=6147; http://id.nii.ac.jp/1291/00006147/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=6147&item_no=1&attribute_id=18&file_no=1

Adelie penguins were used as a biological sampler from late December 1995 to late January 1996 to study biological characteristics of euphausiids in Lutzow-Holm Bay, which is generally covered with fast sea-ice even in summer. Stomach contents and diving behavior of the penguins were examined. Euphausiids accounted for 73% of total wet weight of stomach contents, and fish 27%. Among euphausiids, Euphausia superba occupied 83%, and E. crystallorophias 17%. Females occupied 96% of the total number of E. superba, males only 4%. E. crystallorophias consisted of 73% females, 10% males and 17% juveniles. Adelie penguins might eat nutritionally superior female euphausiids selectively, and/or they could not catch male euphausiids which can swim faster. It was suggested that those individuals which dived deeper ate more euphausiids than fish, and larger E. superba.