Relationships between stable isotopes and trace element concentrations in the crocodilian community of French Guiana

Nondestructive Evaluation of Metal Bioaccumulation and Biochemical Biomarkers in Blood of Broad‐Snouted Caiman (Caiman latirostris) from Northeastern Brasil

“…Mean blood Mn varied from 0.10 µg mL -1 in caimans from AF to 0.85 and 0.47 µg mL -1 in individuals from UA and TR, respectively, 8 and 4 times, respectively, above concentrations from the local reference site AF (Table 1). Blood Mn in four caiman species from French Guiana ranged from 0.03 µg mL -1 in M. niger to 0.09 µg mL -1 in P. trigonatus (Lemaire et al, 2022), concentrations within the range detected in our study at AF, but lower than values verified in C. latirostris from TR and UA (Table 3). Plasma Mn in turtles Phrynops geoffroanus sampled from the Capibaribe River, within similar locations included in our UA, ranged from 0.05 to 0.06 µg mL -1 , lower than our detected concentrations in UA, and within the range of concentrations we detected in AF (Da Fonseca et al, 2023).…”

“…However, the results from our study indicate a wider range of blood Fe levels, from a lower mean of 89 μg mL -1 in caimans from AF and reaching 879 and 1678 μg mL -1 in animals from TR and UA, respectively (Table 3). Animals from UA displayed blood Fe approximately four to five times higher than the range of concentrations reported for other species previously studied (Humphries et al, 2022;Lemaire et al, 2022). Excess iron accumulation can lead to tissue damage and oxidative stress in animals (Clauss & Paglia, 2012;Dos Santos et al, 2022), and further studies exploring this increase in blood Fe in animals from UA and TR are important.…”

“…Camus et al (1998) detected high blood Pb with a mean of 0.80 µg mL -1 in A. mississippiensis fed with prey meat contaminated by lead bullets, and concentrations higher than 0.5 µg mL -1 were considered diagnostic of lead poisoning. In the present study, mean blood Pb varied from 0.01 µg mL -1 in animals from AF to 0.16 and 0.83 µg mL -1 in animals from TR and Data were transformed to wet weight of blood based on blood water content for the species from Lemaire et al (2022). Transformations assumed a blood density of 1 (1 g wet blood = 1 mL wet blood).…”

“…Among analyzed metals, Fe reached the highest blood concentrations, probably due to the large concentration of Fe‐rich hemoglobin in blood. Mean blood Fe levels in four crocodylian species from French Guiana ranged from 285 to 424 μg mL –1 , and this small variation would suggest that Fe regulation would be similar between species, because it is important for hemoglobin function (Lemaire et al, 2022). However, the results from our study indicate a wider range of blood Fe levels, from a lower mean of 89 μg mL –1 in caimans from AF and reaching 879 and 1678 μg mL –1 in animals from TR and UA, respectively (Table 3).…”

“… b Data were transformed to wet weight of blood based on blood water content for the species from Lemaire et al (2022). Transformations assumed a blood density of 1 (1 g wet blood = 1 mL wet blood).…”