Skeletal anomalies in reared Senegalese sole Solea senegalensis juveniles: a radiographic approach

Reared Senegalese sole Solea senegalensis Kaup show a high incidence of vertebral anomalies; however, little is known about its skeletal anomaly profile in the later farming phases. The purpose of this study was to provide a detailed description and quantification of the most common skeletal anomalies in reared Senegalese sole in the juvenile stage by means of computed radiography. A total of 374 Senegalese sole were classified according to the external morphology of the fish as normal or altered and then radiographed in latero-lateral and in dorso-ventral projections. Radiographic evaluation of anomalies focused especially on vertebral body anomalies (VBA) and vertebral column deviations (VCD). The 2 orthogonal projections provided a more complete visualization of the skeleton. Approximately 75% of the individuals showed at least 1 anomaly, while VBA and/or VCD were detected in 48.9% of the specimens. Regarding external morphology, 88% of the fish were categorized as normal, although about 72% of these normal fish displayed abnormalities in radiographies. The most frequent anomalies consisted of deformations of the caudal complex plates (hypurals, parhypural and epural), preurals and caudal vertebrae. Scoliosis was the most prevalent among VCD, affecting the caudal area in almost 15% of the individuals. The anomaly profile at the juvenile stages showed some differences compared to what has been reported previously in earlier stages of development. In light of these results, further investigation into the progression of skeletal anomalies over time and the causative factors at later stages is required.