Abstract:The early development and feeding of larval Sebastes schlegelii were studied at water temperature of 15.4～16.0 ℃, salinity 30～32 and pH 8.4. Results showed that the total length of the newly hatched S. schlegelii larvae was 6.07±0.25mm, with the rudimental yolk sac at abdomen. The total length of 1-day old larvae was 6.21±0.31mm, and the larvae started exogenous feeding of rotifers Brachionus plicatilis which were nourished with unicellular algae (Chlorella sp.). The total length of the 20-day-old post-larvae was 8.81±0.40mm, feeding nauplii of brine shrimp Artemia salina. The relationship between increment in total length (TL) and the age in days (D) was described as: TL (mm) =0.009 6D2 -0.041 5D + 6.750 3 (R2 = 0.987 7). In the starvation tests, negative growth of the starved fish was obvious. The 4th day after hatching is the critical time for a 3-day-old larva to resist starving. The period of no return (PNR) from re-gaining food was about two days. 1-day-old larvae got the highest average feeding intensity at 8∶00, while 5-day-old larvae at 16∶00. Following the increase of catching ability, the feeding intensity reached the highest point at 12∶00 for 12-day-old and 19-day-old larvae. 24-day-old post larvae's feeding intensity reached the highest at 12∶0030-day-old post larvae get the highest feeding intensity from 12∶00 to 16∶00, and the peak at 16∶00 is higher than that at 12∶00 obviously. Larvae showed a feeding incidence of 100% in 24 h. Therefore, these results indicated that there was no obvious feeding rhythm in early development stage of S. schlegelii. Feeding rhythms of S. schlegelii larvae belonged to the all-day feeding with feeding peaks occurred at daytime.
