Commercial products for Artemia enrichment affect growth performance, digestive system maturation, ossification and incidence of skeletal deformities in Senegalese sole (Solea senegalensis) larvae

Proper nutrition at first feeding in marine fish larvae is an important factor for successful larval rearing. However, live prey used to feed marine finfish larvae lack essential fatty acids requiring commercial hatcheries to enrich live prey to provide a balanced diet. Currently, the many commercially available enrichments for live prey present considerable differences in their formulas, and compositions of essential nutrients. Since nutritional requirements are species-specific it is necessary to define those enrichments most appropriate for each species in terms of larval development and quality. This study aimed to evaluate the effect of six enrichments on Senegalese sole larval performance including growth, digestive system development and skeletogenesis, to determine whether any of these products are more suitable for Senegalese sole larval rearing. From 8 to 37 days post hatching (dph), larvae were fed Artemia nauplii previously enriched with six different formulae: Easy Selco© (INVE, ES), Easy Selco© (INVE) half diluted with olive oil (ES/2), Multigain© (BioMar, MG), Red Pepper© (Bernaqua, RP), Aquagrow Gold© (ABN, AGG) and Aquagrow DHA© (ABN, AGD), with the last two being diluted by a third with olive oil. The dietary treatments significantly affected larval growth and performance; larvae fed Artemia enriched with AGG presented significantly higher final dry weight (2.0 ± 0.4 mg), growth and intestinal maturation than larvae fed ES-enriched Artemia (final dry weight: 1.1 ± 0.3 mg). Larvae fed the AGG treatment also were those most advanced in metamorphosis and ossification processes. Larvae fed ES/2, RP, AGD and MG treatments presented intermediary values for all these parameters. No significant effect of the dietary treatments was detected in final survival and incidence of skeletal deformities. We conclude that, among the enrichments tested, AGG is the most appropriate for larvae of Senegalese sole.

► Six commercial enrichments were tested in Senegalese sole larval performance.
► Diets (enriched Artemia) mainly differed in level of n − 3 PUFA and DHA/EPA ratios.
► DHA and EPA levels of 9.5 and 3.1%TFA are advisable for proper larval development.
► DHA/EPA = 3.0, (n − 3)/(n − 6) PUFA = 5.2 were the optimal for larval sole performance.