Skeletal descriptors and quality assessment in larvae and post-larvae of wild-caught and hatchery-reared gilthead sea bream (Sparus aurata L. 1758)

Gilthead sea bream from different Mediterranean hatcheries show a consistent number of skeletal anomalies, mainly in the hemal and caudal body regions. Four hundred and twenty-two hatchery-reared sea bream from Italy, France and Spain were checked for skeletal malformations and meristic counts. The same skeletal descriptors were examined in 72 wild-caught sea bream. Correspondence analysis (CA) was performed to rank groups of hatchery-reared sea bream according to their skeletal abnormalities. The position of each group on the first correspondence axis with respect to the wild-caught specimens was used as a larval quality indicator. Wild phenotype similarity was also tested performing meristic counts and inter-groups meristic differences were illustrated. Results highlighted a quality gap between wild-caught and hatchery-reared specimens, with the only exception being sea bream larvae that were reared in semi-intensive conditions. This larval monitoring method is proposed as a tool for evaluating hatchery larval quality at a morpho-anatomical level