From early development until the completion of metamorphosis, fat snook (Centropomus parallelus) larvae are commonly fed the rotifers Brachionus spp. and Artemia spp. nauplii. In this study, cultivated copepods Acartia tonsa were evaluated as feed for 15-to 45-day-old larvae. Two experiments were performed using twelve 30-L tanks stocked with 3.3 fat snook larvae L-1. Their initial mean weight and length were 1.35 ± 0.01 mg (mean ± standard deviation) and 3.83 ± 0.33 mm for 15-day-old larvae and 2.79 ± 1.2 mg and 6.99 ± 0.88 mm for 31 -day-old larvae. Three dietary treatments were carried out in four replicates, including Rotifer (R), Artemia (A) and/or Copepod (C). Experiment 1 included Diet RA (control), Diet RC and Diet RCA; while experiment 2 included Diet A (control), Diet C and Diet AC. The survival and growth of larvae fed the Diet RCA in experiment 1 were significantly higher than the others. In experiment 2, the inclusion of copepods in the diet did not improve survival and growth, however, larvae fed Diet C had the highest DHA/EPA ratio. We conclude that the copepod Acartia tonsa provides an important nutritional benefit to fat snook larvae undergoing metamorphosis.