Cage culture of Kappaphycus alvarezii (doty) doty and Epinephelus sp.

Abstract

Kappaphycus alvarezii seedlings were cultured in cluster, vertically and horizontally using nylon monofilament rope attached to a bamboo raft installed inside a 5 x 5 m floating cage. Juveniles of Epinephelus sp. were stocked as biological control to grazers.

Specific growth rate (% increase in weight day^-1) and production (g m^-1 line^-1) of Kappaphycus were determined every 45 days and production of Epinephelus was determined after 120 days. Specific growth rate of Kappaphycus alvarezii was significantly affected by the culture technique used. An average specific growth rate of 3.7 %, 3.8 % and 5.3 % was recorded when K alvarezii was cultured in clusters, vertically and horizontally in that order. Horizontal technique of culturing K alvarezii was significantly different from vertical and cluster techniques (DMRT = 0.05). Production (g m^-1 line^-1) of K. alvarezii ranged from 766 to 1,970, (in clusters), 1,110 to 1975 (vertically) and 1,204 to 1,533 (horizontally). These values were significantly affected by the culture month but insignificantly affected by culture technique (DMRT = 0.05). After 120 days of culture, mean weight of Epinephelus sp. was 297 g; % weight gain cage^-1 was 233; survival rate = 68 %; fish production = 5 kg; and FCR = 6.