경상북도 동해 연안에 서식하는 대게 Chionoecetes opilio의 수심 및 월별 출현 양상 변화

Abstract

The Snow crab, Chionoecetes opilio, occurs in the northern part of the Pacific and Atlantic Ocean. C. opilio is a commercially important species in the distribution areas. The occurrence patterns of C. opilio vary by season and water depth. C. opilio was collected in three depth strata (A1: 100-120 m, A2: 120-180 m, A3: 180-220 m) in the eastern coastal sea of Kyungpook, Korea from February 2020 to November 2020. C. opilio was sampled at only A1 from February to April, but at all depth strata from May to November. The average sex ratio (female/(female+male)) was 0.71. The size-frequency distribution was performed by month and depth. The mean carapace width was largest in both sexes in April from February to April in females in October, and in males in November from May to November. The occurrence rate of small immature individuals was highest in A1. The ratio of ovigerous females at 75–80 mm was highest at A2 and A3. There was a significant difference in carapace width size in females by month during September and October and by depth in both sexes. The occurrence rate of immature individuals was higher in A1 than A2 and A3 while that of ovigerous and spawned females was higher in A2 and A3 than A1. Very old shelled females occurred highly in September and October. The occurrence rate of new shelled males was higher throughout the year. The occurrence rate of old shelled and very old shelled females was higher in A2 and A3. Males showed a high rate of the new shell in all water depth strata.