Geometric morphometrics and internal anatomy in sea bass shape analysis (Dicentrarchus labrax L., Moronidae)

The effects of different conditions of larval and postlarval rearing on the external morphology and internal anatomical characters were studied in juv enile and adult specimens of Dicentrarchus labrax L. (Teleostea, Moronidae) in order to assess the potential of a combined methodology in the assessme nt of finfish quality. Differences in the external morphology between two s amples were analysed before their introduction into floating cages and afte r 15 months of common rearing. Shape differences were studied with geometri c morphometrics. Significant differences in shape were found in juveniles. In adults, at the end of the common rearing, differences were smaller but s till significant. The importance of larval rearing conditions in determinin g sea bass juvenile and adult shape is evident as well as a phenomenon of m orphological resilience. On the same specimens, internal anatomical data we re collected from X-rays. In this way, it was possible to correlate fish sh ape with internal anatomical data. Characteristic shapes were associated wi th particular cadres of internal anatomical anomalies, such as head shape a nd anomalies in the cephalic region, a bent body shape and lordosis of the haemal and prehaemal regions, the shape of the caudal region and lordosis o f the caudal vertebral axis. Streamlined wild-like profiles were associated with light anomaly cadres. The use of the combined approach proposed is, t hus, recommended in the description and quantification of shape features an d particularly in the context of fish quality assessment. (C) 2000 Elsevier Science B.V. All rights reserved.