New record of the invasive red-eared slider Trachemys scripta elegans (Wied, 1838) on the Qinghai-Tibetan Plateau, China

Freshwater organisms are facing rapid population declines and substantial extinction risks, and invasive species represent one of the significant drivers of freshwater biodiversity declines. Aquaculture practices and trade activities in China are expansive, and the establishment of nonnative freshwater species is widespread. The red-eared slider Trachemys scripta elegans (Wied, 1838) is one of the world's worst invasive species, and this species is traded nationally both in food and pet markets in China. Red-eared sliders had entered native ecosystems through escapes and intentional releases in China. However, investigations mostly have focused on eastern and central China. Here, we present results of a field survey reporting a new distribution of red eared sliders on the Qinghai-Tibetan Plateau, which is a conservation priority area located in western China. Forty-one individuals in three plots were observed in 2019 and 2020. Four individuals were captured, and no individual was sexually mature. The average carapace length and body weight of the specimens were 70.57 (+/- 13.071) mm and 50.70 (+/- 8.087) g, respectively. Red-eared sliders might negatively influence biodiversity since there are no native testudine species in this region. Thus, we suggest putting more effort into monitoring red-eared sliders and other nonnative species, discouraging unscientific animal release, and emphasizing the threat of releasing nonnative species to the public.