Geometric morphometries 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 juvenile and adult specimens of Dicentrarchus labrax L. (Teleostea, Moronidae) in order to assess the potential of a combined methodology in the assessment of finfish quality. Differences in the external morphology between two samples were analysed before their introduction into floating cages and after 15 months of common rearing. Shape differences were studied with geometric morphometrics. Significant differences in shape were found in juveniles. In adults, at the end of the common rearing, differences were smaller but still significant. The importance of larval rearing conditions in determining sea bass juvenile and adult shape is evident as well as a phenomenon of morphological resilience. On the same specimens, internal anatomical data were collected from X-rays. In this way, it was possible to correlate fish shape with internal anatomical data. Characteristic shapes were associated with particular cadres of internal anatomical anomalies, such as head shape and 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 of the caudal vertebral axis. Streamlined wild-like profiles were associated with light anomaly cadres. The use of the combined approach proposed is, thus, recommended in the description and quantification of shape features and particularly in the context of fish quality assessment. (C) 2000 Elsevier Science B.V. All rights reserved.