Examining the Effects of Chronic Selenium Exposure on Traditionally Used Stress Parameters in Juvenile American Alligators (Alligator mississippiensis)

What are you actually measuring? A review of techniques that integrate the stress response on distinct time‐scales

“…Scutes are keratinized structures that form turtle shells and the tails of crocodilian species. Cort has been found in tail scutes from American alligators Alligator mississippiensis and has been shown to increase following a 2‐hr handling stress, as well as due to long‐term environmental contamination (Finger et al., 2019; Hamilton, Finger, Elsey, Mastromonaco, & Tuberville, 2018; Table S1). It appears, therefore, that scute Cort can change within 2 hr of a stimulus and can also be sensitive to long‐term exposure (weeks‐to‐months; Figure 1), but exploration of this technique is just beginning.…”

Lead, mercury, and selenium alter physiological functions in wild caimans (Caiman crocodilus)

“…Selenium is an essential trace element involved in antioxidant defense and thyroid metabolism which can be toxic in high concentrations (Behne et al, 2000;Ramauge et al, 1996;Rayman, 2000). In the American alligator, Alligator mississippiensis, chronic Se exposure affects stress parameters such as corticosterone levels (Finger et al, 2019). Our results suggest that Se concentrations were not high enough to trigger toxic effects.…”

Non‐invasive measurement of glucocorticoids: The reptile perspective

“…In light of this, levels of CORT have been measured in crocodile tail scutes (Hamilton et al., 2018) and in the shed skin of various snake and lizard species (Berkvens et al., 2013; Carbajal et al., 2018; Carbajal, Fernández‐Bellon, et al., 2014; Zena et al., 2022). Increases of CORT levels in these keratinous tissues are thought to reflect prolonged or repeated stress exposures, as described in American alligator ( Alligator mississippiensis ) subjected to long‐term environmental contamination (Finger et al., 2019). However, contrary to expectations, CORT levels in tail scutes of the same species increased in response to a 2‐h handling stress, thus a single and relatively short‐term stressor (Hamilton et al., 2018).…”

“…Samples are easy to store in plastic or paper envelops at room temperature, a great advantage under field conditions. Other hormone measurements can be made simultaneously in the same sample, and as previously described, samples can be used as indicators of toxicant exposure (Finger et al., 2019). Nevertheless, more work is required to further validate these techniques.…”