Physiology

The skin of Atelopus zeteki contains tetrodotoxin as well as the unique zetekitoxin (Kim et al 1975). This compound makes this species the most toxic of all the Atelopus (Kim et al. 1977, Pavelka et al. 1977). Juvenile A. zeteki are less conspicuously colored than adults, possibly because they have not yet developed the toxins in their skin (Lindquist and Hetherington 1998).