Abstract:Effects of two first-feeding diets(rotifers and fertilized oyster eggs) on the early stage larvae of seven-band grouper Epinephelus septemfasciatus were analyzed and compared with three different feeding modes (A. rotifers, B. oyster eggs, C. mixture of oyster eggs and rotifers) under artificial rearing conditions. Through observations on the feeding situation of 5 dph (day-post-hatching) larvae and gastrointestinal fullness of 4~20 dph larvae, the larval feeding habits and the relationship of light and feeding were discussed. We found that treatment B, which was fed with oyster eggs for 3 days,grew much better than treatment A, which was fed with rotifers only.The specific growth rate of total length in treatment B was 4.969%, which was 2.5- and 2.4-fold of treatments A and C, respectively. Before 10dph, total length, anal distance, and mouth width in treatment B were greater than the other two treatments. Two obvious feeding peaks were found at 9∶00~10∶00 and 13∶00~14∶00 for 5 dph larvae. The light intensity was between 720~1,018 lx and 865~923 lx respectively. The satiation rate of 4dph larvae was lower, in which only 40% reached the Ⅲ level in food intake. Satiation rate of 4~10dph larvae fluctuated, and it began to rise at 10dph, reaching 100% at 13dph.
