Optimization of live prey enrichment media for rearing juvenile short-snouted seahorse

Abstract

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 (ArtDHA/EPA); microalgae-enriched Artemia with a DHA/EPA ratio of 2:1 along with 5% copepods (ArtDHA/EPA5%); and with 10% copepods (ArtDHA/EPA10%)). 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 ArtDHA/EPA5% or ArtDHA/EPA10% (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.