Optimization of Live Prey Enrichment Media for Rearing Juvenile Short-Snouted Seahorse, Hippocampus hippocampus

This study aimed to determine a nutritionally adequate feeding protocol for Hippocampus hippocampus juveniles. In the experimental trial, seahorses were fed copepods from 0-7 days post-parturition (DPP) and, from 8-28 DPP, four different dietary treatments: (copepods (control diet) (Cop); microalgae-enriched Artemia with a docosahexaenoic acid (DHA)/eicosapentaenoic acid (EPA) ratio of 2:1 (Art(DHA/EPA)); microalgae-enriched Artemia with a DHA/EPA ratio of 2:1 along with 5% copepods (ArtDHA/EPA5%); and with 10% copepods (Art(DHA/EPA)10%)). At the end of the trial, juvenile seahorses fed Cop grew significantly more (p < 0.05) (5.1 mg d(-1)) than those on fish-fed diets Art(DHA/EPA)5% or Art(DHA/EPA)10% (3.09 and 3.07 mg d(-1), respectively), or those on the fish-fed ArtDHA/EPA (1.83 mg d(-1)) diet, all of which performed poorly. Data suggest that feeding copepods during the first 7 DPP promotes maturation of the digestive tract of juvenile seahorses, and the addition of a limited amount of copepods to the diet improves H. hippocampus juvenile growth performance when compared with the use of Artemia as a single diet due to the improvement of the essential fatty acid profile in the diets.