Some Ecological Aspects of Antarctic Krill, Euphausia superba in the Antarctic Ocean

남빙양 새우의 생태학적 특성

Spatial distribution patterns of Antarctic krill, Euphausia superba in the Atlantic Ocean sector were seasonally divided into three or four regions; South George Island, Laurie/Coronation Islands and Livingston/King George Islands. Antarctic krill were caught from the surface to about 150 m in depth. The vertical distribution of catch per hour (CPUE) did not show much differences between the 10 m layers, but there were gradually poorer CPUEs as trawl depth increased. It was estimated from relationship between water temperature and CPUE that the Antarctic krill abundance was maximal at water temperatures of $0.8{\sim}1.0^{\circ}C$. The length compositions of Antarctic krill showed that female fish were, on an average, significantly larger than males. Relationship between carapace length and body length, and body length-body weight relationship were well fitted. Sex ratio was $60.3\%$ for male and $39.7\%$ for female with significant difference at the $5\%$ level.

대서양 남빙양 새우의 주된 분포역은 South George Island, Laurie/Coronation Islands와 Livingston/King George Islands 지역으로 공간적인 구분을 뚜렷이 하였다. 어획 수심은 층에서 150 m층까지 달했고, 10 m층으로 구분한 단위노력당어획량의 수직 분포는 층간에 큰 차이가 없었으나 수심이 깊어 질수록 낮아지는 경향을 보였다. 수온과 단위노력당 어획량의 관계로 부터 남빙양 새우는 주로 $0.8{\sim}l.0^{\circ}C$ 범위에서 높은 밀도를 나타내었다. 남빙양 새우의 암수별 체장 조성은 큰 차이를 보여 숫컷의 비율은 작은 체장에서, 암컷의 비율은 큰 체장에서 각각 높았다. 두흉갑장과 체장관계, 체장과 체중관계가 암수별로 추정되었다. 암수별 성비조성은 숫컷이 $60.3\%$, 암컷이 $39.7\%$로서 유의한 차이를 나타내었다.