Survival rate of brown-marbled grouper Epinephelus fuscoguttatus cultured with seaweed Gracilaria changii in multitrophic microcosm models

Groupers (Epinephelus) are economically important fish. Gracilaria changii is a red alga with a high economic value that is widely cultivated in brackish water ponds. In this study, Epinephelus fuscoguttatus and G. changii were polycultured in a multitrophic microcosm model. This study aimed to evaluate the possibility of these two species being cultured multitrophically. In this study we analysed the survival rate of groupers under two seaweed cultivation models (a bottom method and floating method). A control microcosm had no seaweed (grouper monoculture). Fish weight used in the treatment was 135.94 to 359.36 g. The study lasts 47 days at the controlled indoor tanks. The survival rate is lower than the results in previous studies. The condition of water quality parameters was quite good during the treatment, except for ammonia and phosphate. The high ammonia and phosphate content is thought to be the cause of the low survival rate. The survival rate ranges from 47-87%.