Effects of culture conditions on feeding response of larval Pacific red snapper (Lutjanus peru, Nichols & Murphy) at first feeding

Feeding incidence or number of larvae with preys (FIC) and intensity or number of prey per larvae (FIT) at first feeding of Pacific red snapper (Lutjanus peru) larvae was investigated under different conditions: prey type (rotifer and copepod nauplius) and density, nauplii size, light intensity, water temperature, salinity and microalgae concentration. Rotifers were not consumed at any prey density and FIC increased significantly when a high nauplii density (10 > 1, 0.1 mL^-1) and light intensity (2000 > 1000, 500, 0 lx) were supplied. In a multifactorial experiment where light intensity (2000, 2500, 3000 lx), tank colour (grey and black) and prey type (nauplii and a mixed diet: rotifers and nauplii) were tested, a significant difference was found only for light intensity and prey type with a significant interaction between these factors. FIC was significantly higher with nauplii stage I-III than IV-VI and also at 25 °C than at 28 °C. Green water (0, 0.3 × 10⁶ or 1 × 10⁶ cells mL^-1) and salinity (25, 30, 35 gL^-1) did not affect FIC. FIT was not affected by any variables tested except in the density experiment where it was significantly higher at 10 nauplii mL^-1.