Spawning technique of yellowfin tuna (Thunnus albacares) infloating nets cage

Abstract

Tuna is a potential commodity because it contributes the largest fishery export. Tuna aquaculture is one of the steps that can be taken to maintain the stability of tuna fishery production. The aquaculture method using floating net cages is the most productive aquaculture technique. The study has performed in the Central Research of Sea Cultivation and Fisheries Extension Gondol, Bali. The purpose is to know how the technique of spawning yellow fin tuna (T. albacares) in floating net cages. The control issues and obstacles encountered during the process of raising the broodstock yellow fin tuna. Spawning of yellow fin tuna is done naturally. Broodstock female of yellow fin tuna used from catching process that is choosing broodstock candidate of tuna fish with weight 5 kg and length +25 cm. The weight ratio of yellow fin tuna between male and female is 3:1. Water quality parameters for yellow fin tuna larva among others: temperature 29-30 C; pH 8.2; and DO 6.0 ppm. Based on the calculation, the obtained hatching raate of yellow fin tuna is at 75.34% and the Survival Rate is 0%. Artificial feeds used in the maintenance of larvae are Nannochloropsis oculate and Brachionus rotundiformes.