Growth and energy budget of Northern Snakehead Channa argus in relation to ration
Northern Snakehead Channa argus weighing 188.54+13.80 g were fed live Oriental Weatherfish Misgurnus anguillicaudatus at five rations (starvation, 1, 2, 4% body weight per day and satiation) at 28 oC under laboratory conditions to determine its growth and energy budget in relation to ration. The specific growth rate increased linearly with increasing ration and food conversion efficiencies also tended to increase with increasing ration. The proportion of food energy lost in fecal production remained unchanged, but the proportion of food energy lost in nitrogenous excretion tended to decrease with increasing ration, while that going to growth increased. The energy budget at satiation was: 100C＝7.01F + 4.76U + 40.13R + 48.10G, where C, F, U, R and G represent food energy, fecal energy, excretory energy, metabolism energy and growth energy, respectively. The unbalanced error rates in the energy budget (C%) were –9.99-11.94%. Northern Snakehead fed to satiation allocated 45.5% of assimilated energy to metabolism, and 54.5% to growth. Northern Snakehead has a high growth efficiency and a low metabolic expenditure, indicating both aquaculture potential and strong competitive ability for successful invasion.