Scaling of body‐shape quality in reared gilthead seabream Sparus aurata L. Consumer preference assessment,wild standard and variability in reared phenotype

In this study, a scale of quality for the body shape of Gilthead seabream was developed. For this purpose, a questionnaire survey was carried out to study the preferences of consumers for the body shape of seabream. Furthermore, the variation in body shape in reared seabream was studied under two rearing environments (sea cages vs. tanks) and in comparison with wild‐caught individuals. Following the test–retest analysis of reliability, the 22 of 65 participants in the survey presented a significant correlation between repeated evaluations of the same subjects and were classified as responders of high discrimination efficiency or/and reliability (HDR). Geometric morphometric analysis on the evaluation of HDR responders revealed that compared with the fish of fair body shape, fish with preferred body shape were characterized mainly by a more proximal position of the base of the pelvic fins, the anterior base of the anal fin and the anterior dorsal fin. Of the 45 wild‐caught specimens examined, 26 presented a normal lateral line and no obvious skeletal deformities. The body shape of the normal wild‐caught fish was compared with the shape of reared seabream. Results showed that both the origin of fish (wild vs. reared) and the rearing methodology during the on‐growing phase significantly affected the body shape of seabream (P < 0.001). Compared with the reared fish, the wild‐caught fish were characterized mainly by a less prominent belly, slender trunk, smaller head, shorter caudal peduncle and a more posterior‐ventral position of the upper jaw.