Co-culture with Chaetomorpha sp. enhanced growth performance and reduced feed conversion ratio of the giant tiger prawn, Penaeus monodon

The increase in global demand for fishery products has led to a fivefold increase in aquaculture production since 1990. Commercial feed is the highest production cost in intensive aquaculture, and residual commercial feed leads to eutrophication; hence it is important to find a low-cost alternative that has less environmental impact. We investigate the use of the filamentous green algae, Chaetomorpha sp., as a raw feed for giant tiger prawns. The giant tiger prawn, Penaeus monodon was grown in monoculture, and in co-culture with Chaetomorpha sp. to investigate the potential benefits of co-culturing. Five 20-day-old giant tiger prawn juveniles were released in 70-L monoculture and co-culture tanks, and the specific growth rate (SGR) and feed conversion ratio (FCR) were measured after 10 weeks. The final mean body weight of co-cultured prawns was approximately 50 % heavier than that of monocultured prawns. The SGR in co-culture tanks was 4.79 ± 0.08 % day −1 , which was higher than that in monoculture tanks (4.14 ± 0.27 % day −1 ). The FCR was 38.9 % lower in co-culture than in monoculture tanks. The protein content of Chaetomorpha sp. obtained from proximate analysis was almost the same or a little lower than other filamentous green seaweeds; however, the Chaetomorpha sp. has higher fiber and gross energy. These results show that Chaetomorpha sp. has potential for reducing feed costs in prawn intensive aquaculture through co-culturing.