Studies On Feeding Of Oxyeleotris Marmoratus (Bleeker) Larvae

The effects of diet size, light intensity, and starvation on early development and feeding behaviors of Oxyeleotris marmoratus larvae were studied, with the aim to find an optimal way for larvae breeding.The results showed that from hatching to 2 days after hatching (DAF) at the temperature of 30±1℃, the larvae were at the endogenous stage, consuming the yolk-sac for further development. They began feeding in 3 DAP, and the yolk-sac was exhausted in 5 DAF. Therefore, the mixotrophic stage of larvae only lasted for 2 days.The larvae showed obvious selectivity for the size and density of diet. The suitable size of diet for larvae preying ranged from 0.04mm to 0.12mm. The larvae fed effectively under a diet density of 10ind/mL. Moreover, total length(TL) and mouth width(MW) of the larvae had significant effects on the feeding intensity, and the fish fed more intensively with larger TL or MW.The larvae had feeding rhythm. The highest feeding frequency occurred at 16:00~00:00 and a higher one at 04:00~08:00. The feeding frequencies of the fish under the light intensity of 100~500Lx for the larvae of 5 DAH and 10~100Lx for larvae of 8 and 12 DAH increased, compared to those under the light intensity of OLx, 10Lx, and 1000Lx.At the temperature of 30±1℃, the point-of-no-return(PNR) of the larvae occurred at 6~7 DAH. High mortality of the animals appeared in 1~2 days after PNR. The larvae livability obviously decreased due to delayed feeding for more than 2 days.Some morphological indexes of the larvae stagnated when they were starving. However, pectoral angle appeared in 5 DAH in either starved larvae or fed larvae. Accordingly, pectoral angle wasn't the morphological index affected by starvation.