GROWTH PERFORMANCE AND WASTE EXCRETION OF MARBLE GOBY (OXYELEOTRIS MARMORATA BLEEKERj IN RELATION TO DIFFERENT CULTURE SYSTEM AND DIET

摘要

Marble goby (Oxyeleotris marmorata bleeker), a potential profitable aquaculture species in Malaysia and Southeast Asia region, was fed with different diets (live food and minced fish) and cultured separately in partitioned tank (with PVC tubes) attached to a closed recirculating system as an approach to overcome the poor growth performance and disease problems shown by conventional cage and outdoor pond culture systems. This study aimed to examine the growth, feed utilization, protein digestibility and waste excretion of marble goby under the above conditions, and also to evaluate the feasibility of partitioned culture tank in overcoming the fish cannibalistic and territorial behaviors. Fish (100±5g) were fed to satiation once daily for 12 weeks with live tilapia (Oreochromis niloticus), live common carp (Cyprinus carpio) and minced scads (Decapterus russellii), and cultured individually in tank designs of: Big space partitions with PVC tubes (Big-P tubes), Big space partitions (Big-P), and Narrowspace partitions (Small-P). Fish were also cultured in Non-partition with PVC tubes (Non-P tubes) and Non-partition (Non-P) for comparison. Growth offish fed tilapia was significantly higher than those of fish fed carp and scads. Fish cultured in Big-Ptubes and Big-P had significant higher growth and feed intake than other tank designs, whiJe the lowest weight gain and feed intake were shown in Small-P. Feed conversion efficiency (FCE), protein efficiency ration (PER) and productive protein value (PPV) of fish fed tilapia were significantly higher than those of fish fed other diets, whereas fish cultured in Big-P tubes and Big-P showed higher FCE, PER and PPV in tank designs. The survival of fish cultured individually in partitions was 100% comparedto 62.5% and 75% in non-partitions. Fish fed with scads gave the highest waste excretion compared to those of fish fed live food (Tilapia and Carp). Waste excretion was highly correlated with feed intake. Live food, particularly tilapia, was found to bethe preferential diet for marble goby by showing the best growth and nutrient utilization, and exhibited the lowest of waste excretion and N loss comparable to that offish fed trash fish or artificial feed. In addition, culturing the fish individually inspacious partitions with PVC tubes (Big-P tubes) associated with recirculating system was proved to be suitable for marble goby by showing better growth and feed utilization. This type of tank design was able to prevent overcrowding and cannibalism in marble goby.