Association of spinal deformities with heavy metal bioaccumulation in natural populations of grass goby, Zosterisessor ophiocephalus Pallas, 1811 from the Gulf of Gabès (Tunisia)

The present study illustrates an analysis of spinal deformities associated with metal accumulation in natural populations of Zosterisessor ophiocephalus derived from polluted (S1) and unpolluted (S2) areas in the Gulf of Gabes in Tunisia. Three basic types of spinal deformities were detected: kyphosis, scoliosis and lordosis. These basic deformities frequently co-occur. Spinal deformities were observed in 10.72% of the total examined fish (n = 494). Deformed fish were 3.85 times more frequent in S1 than in S2. In both sexes, the highest occurrence of deformities was observed in the 111–120 mm class decreasing thereafter with fish length. Hepatic concentrations of cadmium (Cd), copper (Cu) and zinc (Zn) were significantly higher in Z. ophiocephalus from S1 than those from S2. Comparisons between fish in each site showed that liver concentrations of Cd and Zn were significantly higher in deformed fish than in normal fish. The relationship between metals accumulation and observed spinal deformities as well as the suitability of this kind of studies for environmental monitoring are discussed.