The purpose of this study is to provide information about annual variations in catch size and changes in reproductive biology in the common octopus, Octopus vulgaris, a commercially important species in Jeju Island. Samples were collected from coastal waters of Jeju Island, Korea by coastal trap fishery from January to November 2021. Octopus vulgaris have been decreasing in this region since 1984. The mantle length (ML) ranged from 4.5 to 17.8 cm and body weight (BW) ranged form 88.5 to 2,657.5 g. A χ 2 -test revealed that the number of males was significantly greater than females (χ 2 = 32.712, df = 10, P<0.05). Mature females were found from January to July and male occurred January to August. The gonadosomatic index value was higher from July to August than other months. The relationship between mantle length and body weight was BW = 2.4527ML 2.3139 (female) and BW = 2.6785ML 2.3159 (male). At 50% group maturity, female and male average weight was estimated to be 554.7 g and 330.6 g, respectively.

서 론
재료 및 방법
결 과
    어획실태
    성비, 외투장, 체중의 변화
    생식소의 월별 발달과정과 생식소숙도지수 (GSI)
    성성숙 체중
고 찰
결 론
사 사
References

• 한송헌(국립수산과학원 제주수산연구소 연구원) | Song-Hun HAN (Researcher, Jeju Fisheries Research Institute, National Institute of Fisheries Science, Jeju 63068, Korea)
• 고준철(국립수산과학원 제주수산연구소 연구원) | Jun-Chul KO (Researcher, Jeju Fisheries Research Institute, National Institute of Fisheries Science, Jeju 63068, Korea)
• 김민선(국립수산과학원 제주수산연구소 연구원) | Min Sun KIM (Researcher, Jeju Fisheries Research Institute, National Institute of Fisheries Science, Jeju 63068, Korea)
• 김보연(국립수산과학원 제주수산연구소 연구원) | Bo-Yeon KIM (Researcher, Jeju Fisheries Research Institute, National Institute of Fisheries Science, Jeju 63068, Korea)
• 최정화(국립수산과학원 제주수산연구소 연구원) | Jung Hwa CHOI (Researcher, Jeju Fisheries Research Institute, National Institute of Fisheries Science, Jeju 63068, Korea) Corresponding author