2006년 1월부터 12월까지 충남 보령시 외연도 앞바다에서 형망으로 채집된 갈색띠매물고둥(Neptunea(Barbitonia) arthritica cumingii)을 대상으로 번식생태를 조사하기 위하여 생식소지수, 비만도지수, 생식주기, 군성숙도 및 성비를 조사하였다. 산란기를 간접적으로 추정하기 위해 조사한 생식소지수(GI)의 변화는 생식소 발달 단계와 밀접한 관련을 보였다. 생식소지수(GI)는 암, 수 모두 2월부터 증가하기 시작하여 4월에 최대값
Gonad index (GI), conditon index, the reproductive cycle with gonadal development of the Neptunea (Barbitonia) arthritica cumingii, were investigated histologically, based on the samples which have been collected from the subtidal zone of Oeyeondo, Boryeong, Korea from January to December, 2006. Neptunea (Barbitonia) arthritica cumingii is dioecious and oviparous. Monthly changes in the gonad index (GI), studied for determination of spawning period, were closely associated with gonad developmental phases. The GI reached a maximum in April, and gradually decreased from May to August due to spawning. The gonadsomatic index and condition index showed similar patterns to gonad developmental phases and the spawning period. The reproductive cycle according to gonad developmental phases of this species can be classified into five successive stages in females and males: in females, early active stage (September to October), late active stage (November to February), ripe stage (February to June), partially spawned stage (May to August) and recovery stage (June to August); in males, the early active stage (September to October), late active stage (November to February), ripe stage (February to June), copulation (April to July), and recovery stage (July to August). Spawning occurred between May to August in females and April to July in males, and spawning peak in females was observed between June and July when the seawater temperature rose to above . Percentages of first sexual maturity of female and male snails ranging from in shell height were over 50%, and 100% for snails over 60.1 mm in shell height. The sex ratios of females to males were not significantly different from a 1:1 sex ratio.