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Background: Giant gourami (Osphronemus goramy Lacepede, 1801) has become popular aquaculture in Indonesia. However, information on the feed used is minimal. This study analyzed the change in feeding nutrition, fish growth, feed efficiency, and body-carcass using product formulated from water coconut, palm sap sugar, and fungus. Methods: A total of 2,000 ml coconut water and 1,000 ml of palm sap sugar solution were formulated. Each product formulated was added with 6 g of Aspergillus niger (called product P1), 6 g of Rhizopus oligosporus (called product P2), and 6 g of Saccharomyces cerevisiae (called product P3). Commercial feeds supplemented with P1, P2, and P3 products are designated P1, P2, and P3 diets. Commercial feed added to freshwater is called the P4 diet (placebo). Their dosage is 300 ml/kg of feed. Gurami sago juveniles (initial weight 50±2.5 g and length 13.2±0.4 cm) were stocked in triplicate nets (2×1×1 m) in a freshwater concrete pond with a stocking density of 30 fish/net, an initial feeding rate of 3% per day until study termination. Results: Our results support our hypothesis that different product formulations have a significant effect (p<0.05) on growth performance and feed efficiency. At the same time, supplementing commercial feed with varying formula products has a significant impact (p<0.05) on the fatty acid composition of the diets and carcass body of gurami sago. Conclusion: Diet P2 contains a higher concentration of fatty acids to increase body weight, feed efficiency, and the best carcass fatty acid composition than other experiments for sago gurami reared in freshwater concrete ponds.

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Background: The giant gourami sago strain (Osphronemus goramy Lacepède) has been approved in 2018 as a candidate for freshwater aquaculture in Indonesia. However, information on the species’ reproduction is minimal. This study analyzed the reproductive characteristics of the gourami sago strain broodfish to provide basic knowledge for a future hatchery development strategy. Methods: A total of 10 female and 10 male mature gourami sago strain broodfish were measured for body weight and length, and were evaluated for their reproductive characteristics.  Breeding fish were spawned naturally in a 2×1×0.6 m concrete pond with a male-female sex ratio of 1:1. Egg weight and diameter were measured in 25 eggs per female using, respectively, ACIS AD- 600i scales with 0.01 g accuracy, and a microscope (Labo model L-711) using Canon Digital Camera Software 3 . Semen was collected using plastic syringes in 3 mL aliquots, then placed in an insulated ice-cooled container, and analyzed within two hours of collection. Results: Average weights of female and male broodfish before spawning were 2180±159.78 g and 3060±134.99 g, respectively. The relative fecundity and egg diameter were 1029±36 eggs kg-1 and 2.42±0.05 mm, respectively. The hatching rate and embryo survival to an eyed-egg stage were respectively 76.40±2.27% and 94.76±0.42%.  Sperm characteristics showed that volume was 0.60±0.12 ml kg-1 and percentage of motile sperm was 70.04±2.27%. Female broodfish weight after spawning was strongly correlated with the weight before spawned (r2 = 0.999) and absolute fecundity was also strongly correlated with female broodfish weight before spawning (r2= 0.921). Sperm concentration was moderately correlated with sperm motility (r2 = 0.556) and duration of sperm motility (r2 = 0.502). Conclusions: The gourami sago strain broodfish has suitable reproductive characteristics for the development of hatcheries. Successful natural spawning should be followed by larval weaning and feeding technology to increase growth and survival.

Background Aquaculture systems for giant gourami, Osphronemus goramy Lacepède (1801), have significantly improved fish production yields and food security in Indonesia. However, these systems also cause serious problems in terms of eutrophication in waterbodies. This study analysed the nutrient loading and farm characteristics of giant gourami in floating cages in Lake Maninjau. Method A total of 20 floating cages were used to record these nutrients in feed supply, female and male juvenile fish, dead fish and harvested fish to estimate nutrient loading. Data on the harvested fish, production cycle, stock number and cage capacity were used to estimate the stocking density, feeding rate, feed efficiency, and net fish yield, and the relationship between feed supply and nutrient loading and farm characteristics was analysed by least squares regression methods. Results A total of 20 floating cages released nutrients into waterbodies at an average rate of 236.27±60.44 kg/cycle for C, 84.52±20.86 kg/cycle for N and 8.70±3.63 kg/cycle for P. On average, fish production for each floating cage (±SD) was 1226±282 kg wet weight/cycle, and the net fish yield was 12.63±2.82 kg/m3/cycle. Survival rates ranged from 86.33 to 95.27%/cycle. The production cycles varied from 160 to 175 days with feed conversion ratios between 1.60 and 1.75, feed conversion efficiencies were between 0.58 and 0.63. The production parameters that had strong relationships with the net fish yield were feed supply (r2=0.960), stocking rates (r2=0.924) and feeding rates (r2=0.961). In contrast, the length of the production cycle was not strongly related to the net fish yield (r2=0.187). Conclusion Nutrient loading from the supplied feed was greater than that from the harvested fish, juvenile fish and dead fish. Increasing the net fish yield in floating cages was better predicted by the stocking densities and feeding levels than by the other factors.