Metallothionein and metal levels in cytosol of liver, kidney and brain in relation to growth parameters of Mullus surmuletus and Liza aurata from the Eastern Adriatic Sea

Two wild fish populations, Mullus surmuletus (striped red mullet), as a bottom and Liza aurata (golden grey mullet), as a pelagic species, were sampled in Kaštela Bay, Middle Dalmatia. Metallothionein (MT) and metal content (Cu, Zn, Cd) was determined in heat treated supernatants (S50) of fish tissues. MT levels were statistically different in liver and kidney of sampled species, with highest value in kidney of M. surmuletus (31.1&plusmn ; 7.96 &#956 ; g mg-1 proteins). Metal levels are statistically different between all tissues. Highest metal concentrations are in liver cytosols, especially of Cu in L. aurata (6.46&plusmn ; 3.45 &#956 ; g ml-1 S50). High positive correlation of MT and cytosolic metals is established with Zn in liver of M. surmuletus (0.95) and with Cu in liver of L. aurata (0.69). Total length, body weight and age are mostly correlated biometric parameters with MT and soluble metal concentrations. MT and metal levels increase with age in liver cytosol of both species.