Gonadal maturation and trace metals in the mangrove oyster Crassostrea corteziensis: seasonal variation

The concentration of nine trace metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn) associated with the gonadal and somatic (non-gonadal) tissues throughou t the reproductive cycle of the oyster Crassostrea corteziensis (Hertlein) have been studied. The metal concentration in this oyster exhibited signifi cant seasonal variations. The highest concentrations of Cu, Ni, Ph and Zn o ccurred in November when the oyster was in the resting phase, while the max imum of Mn was recorded in March when the population was predominantly in g ametogenic activity. The elevated values of Cd and Fe were presented in Sep tember during the post-spawning phase. Only Mn showed a good positive corre lation with the maturation of the organism. This last result suggests that Mn may perform some function during the gonadal maturation or prespawning. (C) 1999 Elsevier Science B.V. All rights reserved.