Gonad maturation and spawning of Gamat sea cucumber, Stichopus sp. reared in captivity Ketut Maha Setiawati1), Jhon Harianto Hutapea1), Zeny Widiastuti2), Made Buda1) and I Nyoman Adiasmara Giri1)
1) Research Center for Fisheries, Indonesia National Research and Innovation Agency
2) Brackishwater Aquaculture Development Center-Situbondo
Abstract
The exploitation rate of sea cucumber (Stichopus sp) has reached over exploitation, resulting in natural population decline. Therefore, a cultivation effort is needed to maintain the Gamat processing business and also as an effort to reduce the exploitation of the natural population. Understanding the spawning profile of sea cucumber in captivity was the main objective in this study. Observation include broodstock growth, spawning pattern, number of eggs produced, eggs diameter and hatching rate. Candidate broodstock is obtained from the Northern Bali Sea and then reared in a fiber glass tank with 4 qubic meters. During rearing, water exchange rate was 400 % per day candidate broodstock were fed with Sargassum sp and Ulva sp at a dose of 2.5 % of the body weight per day. Spawning is carried out from 2020 to 2022. The number of broodstock spawned were 20 individual per month with an average body weight size 0f 260 +/- 90 g. The results showed that sea cucumber broodstock can spawned throughout the year with the number of eggs varying from 105,000-3,000,000 eggs, egg diameter 180-270 micro meter and hatching rate ranging from 38.0-99.5 %. Spawning carried out every new moon for 3consecutive years shows a tendency to decline the frequency of spawning.
Keywords: Eggs diameter, hatching rate, number of eggs, spawning profile, Sticophus sp
