The inhibitory situational analysis of some feed ingredients for meagre, Argyrosomus regius (Asso 1801) larvae and evaluation for diet formulations

Abstract

Meagre, Argyrosomus regius (Asso 1801) is an important alternative species in aquaculture. The in vitro assay provides practical assessments for the evaluation of feed ingredients. In this study, the inhibition degrees of feed ingredients (fish meal-FM, fish hydrolysate-FH, krill meal-KM, soybean meal-SM, wheat gluten-WG, corn gluten-CG and sunflower meal-SF) on protease activities of meagre larvae were determined. Larvae were sampled from the first day of opening the mouth (3 days after hatching-DAH) until the end of the weaning (32 DAH) from the Egemar Hatchery (Aydın-Turkey). Larvae of the total length were measured as 3.19 ±0.02-21.61 ±0.22 mm and weights were calculated as 0.53 ±0.02-118.00 ±1.09 mg at 3 and 32 DAH, respectively. Protease activities of larvae were the lowest as 5.95 ±0.60 U/mg protein (15 DAH) and the highest as 211.21 ±12.56 U/mg protein (7 DAH), respectively (P<0.05). The lowest inhibitions degrees of feed ingredients were observed at 15 DAH except for SF. The use of FH in the diet formulations of meagre larvae should be paid attention. While CG and SF are advised, SM does not seem to be suitable.