Experimental Starvation on Pomoxis nigromacufatus Larvae and Definition of the Point of no Return

Effect of starvation on the feeding, growth and development of Pomoxis nigromacufatus larvae were investigated at 19.5-22.8℃ using an experimental ecological method.The tolerance to starvation and the point of no return (PNR) of P.nigromacufatus larvae were determined.The results showed that (a) the initial feeding of the larvae started at 6days of age, the yolk sac disappeared at 8-day-old, the mixed dieting period was about 2days, and the larvae were vulnerable to starvation stress; (b) the highest initial feeding rate of the larvae occurred when they were 9-day-old, the PNR was determined to be 11 to 12days after hatching, their feeding last for merely 4to5 days, and they died one day after PNR;and (c) as compared with their counterparts under normal feeding, the starved larvae were slow to utilize yolk sac and fat globules, their growth became stagnant or regressive as the starvation continued, and they began to show pectoral angles at PNR with a series of apparent, hunger-induced morphological and behavioral characteristics.