A survey of 29 wetlands in the Fraser River of British Columbia suggested that red-eared slider turtle, Trachemys scripta elegans is well established and more widely distributed. Their history, habitat requirements, relative density, size distribution were coexisted with the Western painted turtle, Chrysemys picta bellii. According to the International Union for Conservation of Nature (IUCN), invasive species are one of the most important causes of biodiversity decline at a global scale. Pet voluntary introductions are made by public and usually concern only one or two individuals per occasion. Hatchling of T. s. elegans has been massively exported from the United States America (USA) to European and Asian countries to be sold as pets. Recent studies with T. s. elegans have shown that exogenous estradiol-even when applied to eggshell was affecting sex development during embryogenesis. Aroclor produced most powerful effects, shifting the ratio of females almost twofold. The daily and seasonal changes in ventilation and breathing pattern resulted solely from daily and seasonal oscillations in metabolism or also from changes in chemo-reflex sensitivity.