Growing Trial of Gilthead Sea Bream (Sparus aurata) Juveniles Fed on Chironomid Meal as a Partial Substitution for Fish Meal

Insect meal, derived from chironomid larvae collected from aquatic environments, was included in feeds for gilthead seabream juveniles (75 ± 1.1 g) through 90 days of growing trial. Three feeds, one control (L1) and two experimental diets (L2, L3), were analysed and formulated as 26 isonitrogenous (45%) and isolipidic (13%). In L1, protein source was mainly represented by soybean meal (32%), followed by fish meal (20%), wheat meal (20%), gluten corn (17%) and haemoglobin (11%). In L2, soybean meal was increased (33.5%), followed by gluten corn (21%), 29 wheat meal (14%), haemoglobin (11%), whereas fish meal source was reduced (15%) to include chironomids (5%). In L3, fish meal was further reduced (8%) and chironomid meal was increased to 10% of protein source. The L2 and L3 groups showed similar growth performances respect to the L1 group. Feed conversion rate was favorable in all the groups ranging from 1.18 (L1) to 1.22 (L3). Survival varied from 93.62% (L3) to 94.31% (L1). Feed palatability showed similar result among the diets. Although the inclusion of chironomid meal was used in small quantities, our results suggest a significant advantage saving until 50% fish meal replaced with chironomid meal for growing of gilthead seabream.