Development, growth, and yolk utilization of hatchery-reared red snapper Lutjanus campechanus larvae

The development of yolk-sac larvae of red snapper Lutjanus campechanus from endogenous utilization of nutrient sources to the development of feeding ability is described, with the aim of better understanding the high mortalities observed at first-feeding. Larvae from several spawns were reared at a salinity of 31 and a temperature of 28degreesC. Yolk utilization rate, changes in body parameters and the development of morphological characters were observed. Maximum standard length (L-S) and body depth were observed concurrently with yolk-sac exhaustion at 56 h post-fertilization (hpf). A decrease in L-S, body width and body depth was observed following yolk-sac exhaustion. Orbit pigmentation, followed by jaw articulation, were observed at 65 hpf. Substantial cranial and body cavity development occurred in the absence of visible yolk material. Complete absence of visible yolk-sac material and less than 2% of the oil globule volume at hatching were observed at the time of development of feeding ability. This indicates an absence of a transitional feeding period and the critical nature of first-feeding in this species within controlled environments.