Application of Young Coconut Water in Gourami (Osphronemus gourami) Egg Incubation: Impacts on Hatch Rate, Larval Viability, and Growth Performance

Gourami (Osphronemus gourami) is a freshwater fishery commodity with high economic value in Indonesia. One of the critical stages in seed production is egg hatching, which determines hatchability, survival, and larval growth. This study aimed to evaluate the effect of adding young coconut water (YCW) to the hatching medium on the hatching success of gourami eggs. YCW is known to contain electrolytes, vitamins, minerals, and bioactive compounds such as phenols that have antioxidant and antimicrobial properties, thus potentially improving the quality of hatching media. The study was conducted using a completely randomized design with four treatments of young coconut water concentration (0, 15, 25, and 35 ml/L) and three replications, and the parameters of hatching rate (HR), survival rate (SR), absolute length and weight growth, and specific growth rate (SGR) were observed. The results showed that YCW treatment significantly increased the hatching rate up to 100% (P<0.05) compared to the control (97.67%), with the optimal effect at 25ml/ L treatment. The highest survival was recorded at the 15 ml/L dose (93%), while the 35ml/ L dose significantly reduced SR (80.33%), indicating a negative correlation at high doses. Meanwhile, growth and SGR showed no significant differences between treatments (P>0.05), although there was an increasing trend with dose. Water quality in all treatments was within the tolerable range. The addition of young coconut water to the hatching medium can be an effective natural alternative to increase the hatching success of gourami eggs and to support the development of environmentally friendly hatchery technology.