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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 28°C. 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 postfertilization (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. KEY WORDS: Red snapper · Larval development · Yolk utilization · Endogenous reservesResale or republication not permitted without written consent of the publisher

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Two experiments addressed the spontaneous spawning of red snapper, Lutjanus campechanus, under controlled temperatures and photoperiods and the effect of broodstock diets supplemented with oils rich in polyunsaturated fatty acids. In Experiment 1, broodfish were fed a standard diet (ST1) and one enriched with menhaden oil (ER1) over a 355-d period. ER1-influenced egg fatty acid profile, however, did not positively influence egg production. Both diets produced highly viable eggs and larvae but results varied within treatments. In Experiment 2, broodfish were fed either a standard diet (ST2) or one supplemented with oils (ER2) rich in docosahexaenoic and arachidonic acid using a 203-d cycle. Both treatments produced eggs but fertilization rates ranged 0-10%. There was no clear influence of the diets on egg fatty acid profiles. These results indicate that red snapper can spawn spontaneously in tanks under controlled environmental conditions and produce viable eggs and larvae when fed diets based on squid, shrimp, and fish. The fatty acid composition of the diets was reflected in the eggs to some degree, but the oil enrichments did not further enhance the reproductive performance and egg quality under the conditions of this study.