Trace metals in the Mexican shrimp Penaeus vannamei from estuarine and marine environments.

Trace-metal concentrations (Fe, Mn, Ni, Cu, Co, Cd, Cr, and Zn) were measured in estuarine postlarvae, juveniles, and marine adults of the shrimp Penaeus vannamei collected along the Pacific coast of Mexico. With the exception of Fe, the trace-metal concentrations fell within the ranges of similar organisms collected elsewhere. Size-dependent relationships were observed only for Ni, Fe, and Zn and varied depending on the element considered. Small individuals had higher concentrations of Fe and Ni than larger individuals. For Zn, the opposite tendency occurred. This may reflect different metabolic requirements of young and old shrimps.