Directional asymmetry (DA) is a widespread yet often overlooked feature of animal morphology. Here, we report a consistent right-biassed asymmetry in the crystalline lenses of the thornback ray Raja clavata. Across 71 individuals sampled from the Strait of Sicily, 24% exhibited lens asymmetry, and in all cases, the right lens was larger. This pattern, supported by binomial and distributional tests, represents the first evidenc...

The European eel (Anguilla anguilla), a catadromous species currently listed as Critically Endangered by the IUCN, is undergoing a severe continental decline. Among the multiple contributing factors, chemical contamination of aquatic environments—particularly by heavy metals—plays a major role. This study analyzed the concentrations of 16 trace elements in the muscle tissue of A. anguilla specimens collected from three ecologi...