Abstract

Information is scarce on the optimal rearing conditions for red snapper (Lutjanus campechanus). Rearing and large scale production of red snapper have been hampered because it is difficult to produce enough prey of appropriate size to ensure survival of larvae to a size at which they can consume Brachionus plicatilis and artemia nauplli. Secondly, it has not been possible to rear snapper larvae in small containers for short term experiments; all successful rearing to date has been in containers >=200 L. We evaluated the relationship between copepod nauplii available per fish on the day of first feeding and survival of red snapper. Additionally, we assessed the suitability of various types/sizes of containers, from to L black plastic containers through 20 L polycarbonate containers to 200 L black plastic containers filled with 100 L of seawater, for rearing snapper larvae. There was a significant positive correlation between prey number per fish on the day of first feeding and survival of snapper (Spearman'srank correlation, rs=0.83,n=10,P=0.013). Similarly, larval survival was positively correlated with number of copepod nauplii/mL (rs=0.73,n=10,P=0.029).\Rearing studies using 10 L and 20 L black plastic containers resulted in 100% mortality of larvae by day 7 post-hatch. Experiments carried out using polycarbonate containers and 200 L black tubs containing 50 L or 100 L of brown seawater resulted in 0 to 34% larval survival. Number of larvae that survived was significantly higher in polycarbonate containers (mean=46.7±21.9 S.E.) than in black tubs with 50 or 100 L of water (mean=5±4.67 S.E.) [Unpaired t-test value=2.622,df=5,P=0.047]. Differences in larval survival in the culture containers probably resulted from interactions between the amount of light present in the containers and container color that, presumably, affected prey visibility to, and therefore consumption by larval snapper.

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