A BIOENERGETICS MODEL FOR AN AIR-BREATHING FISH, CHANNA-STRIATUS

Food consumption, standard metabolism, and growth of juvenile snakehea d, Channa striatus, a cannibalistic and air-breathing fish were measur ed at 24-26 degrees C under controlled laboratory condition. Snakehead weighing 3.2-29.5 g were evaluated, and were fed smaller snakehead. B ased on our observations, we determined bioenergetics relationships be tween specific food consumption, metabolic rates, and body weight. The se values, along with other published parameter values allowed us to c onstruct a bioenergetics model for snakehead. We then verified our mod el with growth and food consumption measurements from an independent f eeding trial. Predicted fish growth closely matched observed growth. O ur model underestimated cumulative food consumption when a constant ac tivity value was used, but consumption estimates improved when we used nonconstant activity values (1-5 times of standard metabolism). Predi cted fish maintenance ration was 1.7% of body weight per day. Food con version efficiency was greatest (0.59) when fed 2% body weight daily, but declined when daily consumption exceeded 6% body weight. This mode l provides a useful approach for assessing food requirements of snakeh ead under controlled condition.