Sea Cucumber Meal as Alternative Protein Source to Fishmeal in Gilthead Sea Bream (Sparus aurata) Nutrition: Effects on Growth and Welfare

The aim of the present study was to evaluate the effect of sea cucumber meal on gilthead sea bream growth. Two diets were used: a fishmeal based diet (control) and a diet containing 18% of sea cucumber meal inclusion (HM). A 100-days growth trial was carried out (120 fish, initial mean body weight of 35.28+/-9.31 g). The experimental plan used was monofactorial, balanced with three replicates for two experimental treatments (fish diet). The diets were isolipidic (CL 15.80+/-0.5%), isonitrogenous (CP 49.70+/-1.0%) and isoenergetic (GE 20.00+/-1.0 MJ kg(-1)) and feeding rate was 1.5% of biomass. At the end of the trial, growth performances parameters, digestive enzymes (liver and intestinal), haematological parameters, Na+/K+ ATPase activity were measured. Oressigenic and anoressigenic brain neuropeptides were also analyzed in order to investigate other effects of food intake in fish. Productive parameters, blood plasma parameters, enzyme activities and neuropeptides expression were not affected by the introduction of sea cucumber meal in fish feed thus showing that HM can be used as a partial substitute of fish meal in sea bream nutrition