Freshwater aquatic reptiles (Testudines and Crocodylia) as biomonitor models in assessing environmental contamination by inorganic elements and the main analytical techniques used: a review

Abstract

chosen for each group (37%), we observed an increase in the use of non-destructive matrices in both groups (scale, blood, tail muscle, carapace). The majority of analysed studies used HNO 3 for the sample decomposition, with the majority of analyses being performed using atomic absorption spectroscopy (53%). Mainly blank controls (19%), analyte recovery (18%) and replicates (18%) were used as methods of validating analytical procedures. Furthermore, the studies used certified reference materials, which measure the accuracy of the methods used. We conclude that the increase in the use of aquatic reptiles in environmental monitoring research is mainly due to their ability to reveal integrated changes in ecosystems, aiding in environmental public policy decision-making and effective management plans.

Maternal provisioning interacts with incubation temperature to affect hatchling mercury exposure in an oviparous reptile

“…Total mercury concentrations in both blood and dermis were significantly correlated with THg concentrations in other tissues, except for residual yolk. There is an impetus for non-lethal mercury sampling [42,62,66,67], and blood has proven a reliable indicator, showing high levels of correlation with internal organs (blood–muscle: R 2 = 0.9499 [59]; blood–muscle: R 2 = 0.82, blood–liver: R 2 = 0.79 [66]). We did not observe such high correlation coefficients, suggesting that although blood could potentially be used as a non-lethal indicator of mercury in hatchlings, this relationship appears stronger in adults.…”

“…THg concentrations in liver ranked comparatively low among all tissues, contradictory to high liver THg concentrations reported in adults [54,55,[59][60][61]. The liver is generally considered the main site of mercury storage and depuration [47,54,55,59,60,62], presenting two possibilities. First, liver THg concentrations observed in this study reflect differences in exposure route, with maternally deposited mercury being found in different tissues (e.g.…”

Total Mercury Content in the Tissues of Freshwater Chelonium (Podocnemis expansa) and a Human Health Risk Assessment for the Amazon Population in Brazil

“…The bioaccumulation of toxic metals by reptiles results from surface contact with the water and food chain [47,63,64], and the concentrations depend on the environmental levels of trace metals in the habitat, since they are absorbed and stored in the tissues [65]. Researchers have shown that the mercury concentrations in the muscles of freshwater animals varies widely depending on the capture location [59,66].…”

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

“…The broad‐snouted caiman ( Caiman latirostris ) is widely distributed in South America, from the Northeast and across the Southeast and South of Brasil to Uruguay, northeast Argentina, southern Paraguay, and southwest to Bolivia (Verdade & Piña, 2007). Caiman latirostris has been used as a bioindicator of environmental contamination using chemical (Dos Santos, de Sousa Correia, & dos Santos, 2021), biochemical (Burella et al, 2018), genotoxic (López González et al, 2013; Poletta et al, 2011), histological (Stoker et al, 2008), and endocrine (Stoker et al, 2003) blood parameters. Blood samples offer a highly valuable approach for assessing the accumulation and biological consequences of contaminants in vertebrates, while avoiding destructive procedures (Fossi et al, 1998; Grillitsch & Schiesari, 2010).…”