World Aquaculture Singapore 2022

November 29 - December 2, 2022

Singapore

DETERMINING THE OPTIMAL STOCKING DENSITY OF BOTH JUVENILE AND EARLY GROWER HYBRID GROUPER – TIGER GROUPER Epinephelus fuscoguttatus x GIANT GROUPER Epinephelus lanceolatus

 Ian C. JueQi*, Jack M. James, Chassie T. Tse Tjie and Crystal L. Liwen

 Pontus Research Group       

 Marine Aquaculture Centre (MAC)

 St John’s Island, Singapore

 icj@pontusresearch.com

 



Hybrid Grouper – Tiger Grouper Epinephelus fuscoguttatus X Giant Grouper Epinephelus lanceolatus are one of the more commonly aquaculture species. Its fast growth rates, resistance to disease, high survival and good economic value makes it an important species to be farmed commercially.

A 6.5-week performance trial was conducted with 1575 mixed sex fish (± 30 grams) for juvenile (30 – 100 grams) hybrid groupers and a 4-week performance trial were conducted with 2300 mixed sex fish (± 150 grams) for early grower (100 – 300 grams) hybrid grouper. The aim of this study was to examine the optimal stocking density and growth performance for each stage, and to mimic a commercial production. Fish were batched weighed and randomly assigned and stock in 300-liter and 1000-liter fiberglass tanks, with a recirculating aquaculture system. Ammonia, nitrite, nitrite, temperature, dissolved oxygen, and pH was measured twice a week. Fish was fed 3 times a day to satiation with a commercial grouper feed and light: dark was at 8-9 hours light: 15-16 hours dark.

After 6.5 weeks, juvenile groupers kept in density group D5 (9 kg/m3) and D6 (10.50 kg/m3) showed the best performance, with actual end densities of 37.48 kg/m3 and 44.20 kg/m3. Following the 4-week trial, the early grower groupers in density group D2 (25 kg/m3) and D3 (30 kg/m3) showed the best performance, with actual end densities of 45.43 kg/m3 and 46.94 kg/m3.