Toxicokinetics of selenium in the slider turtle, Trachemys scripta

Area of Science:

• Environmental Toxicology
• Wildlife Health
• Ecotoxicology

Background:

• Selenium (Se) is an essential element with potential toxicity to wildlife.
• Toxicity data for selenium in poikilothermic amniotes, such as turtles, is limited.
• Understanding selenium toxicokinetics is crucial for assessing risks to turtle populations.

Purpose of the Study:

• To investigate selenium toxicokinetics and toxicity in juvenile slider turtles (Trachemys scripta).
• To evaluate the suitability of non-destructive tissues for predicting selenium levels in target organs.
• To inform conservation strategies regarding selenium exposure in turtles.

Main Methods:

• Dietary exposure of juvenile slider turtles to selenomethionine (SeMet) for eight weeks.
• Analysis of selenium accumulation in non-destructive (carapace, scutes, skin, blood) and target tissues (kidney, liver, muscle).
• Monitoring of body condition, survival, and selenium species in tissues.

Main Results:

• Turtles efficiently accumulated SeMet from their diet, with higher dietary selenium leading to greater tissue accumulation.
• Selenomethionine was the predominant selenium species found in turtle tissues.
• No adverse effects on body condition or survival were observed in turtles exposed to selenium.
• Non-destructive tissues showed potential for predicting selenium levels in key organs.

Conclusions:

• Juvenile slider turtles can accumulate significant levels of dietary selenium without apparent adverse effects.
• Non-destructive tissue sampling offers a promising, non-invasive method for biomonitoring selenium exposure in turtles.
• Reptilian species may exhibit differential sensitivity to selenium, warranting further investigation.