Effects of delayed initial feeding on growth and survival of Chinese sturgeon (Acipenser sinensis Gray, 1835) larvae

摘要

The goal of this study was to determine the point of no return (PNR) for Acipenser sinensis larvae and their growth in relation to delayed initial feeding. During the experiment at 23.2 +/- 0.8 degrees C, the initial feeding rates increased from 7.7 to 73.7% in larvae at age 7-12dph (days post-hatch). When delayed initial feeding was conducted at 14dph, the initial feeding rate was as low as 37.3%. The rate declined even further thereafter, thus the PNR was assumed to have been reached by 14dph. The survival rates were more than 80% at 7-2dph, thereafter falling dramatically. Total lengths of larvae and body weights increased gradually and reached the maximum at 12dph, then decreased and were even less than those at 7dph. It was concluded that the optimal time for exogenous feeding was at 9-10dph.