Tissue-Specific Metal Accumulation in Two Crocodylusmoreletii from Southeastern Mexico: A Case-Based Assessment.

This study reports tissue-specific concentrations of cadmium (Cd), mercury (Hg), copper (Cu), and zinc (Zn) in two deceased Crocodylus moreletii from Southeastern Mexico. One was an adult male struck by a vehicle; the other, a severely emaciated juvenile female. Organs, plasma, and caudal scutes were analyzed using atomic absorption and voltammetry. The juvenile exhibited extremely high concentrations of Cd (137.55 µg/g) and Zn (210.27 µg/g) in kidney tissue, exceeding values reported in other crocodylian species. Scutes and plasma also reflected internal metal burdens, supporting their use as non-destructive matrices. Comparisons with published data suggest these are among the highest concentrations recorded in crocodylians, raising concern about localized environmental contamination. The findings reinforce known tissue-specific accumulation patterns and highlight the value of opportunistic sampling for internal tissue assessment in protected species. This study contributes rare toxicological data for C. moreletii and emphasizes the need for continued biomonitoring in understudied tropical freshwater habitats.