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

Abstract

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, <em>Chaetomorpha</em> sp., as a raw feed for giant tiger prawns. The giant tiger prawn, <em>Penaeus monodon</em> was grown in monoculture, and in co-culture with <em>Chaetomorpha</em> 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 <em>Chaetomorpha</em> sp. obtained from proximate analysis was almost the same or a little lower than other filamentous green seaweeds; however, the <em>Chaetomorpha</em> sp. has higher fiber and gross energy. These results show that <em>Chaetomorpha</em> sp. has potential for reducing feed costs in prawn intensive aquaculture through co-culturing.