Sulphur molly

The sulphur molly (Poecilia sulphuraria), locally known as molly del Teapa, is an endangered species of poeciliid fish. It is endemic to the sulfur springs of the Mexican states of Chiapas and Tabasco and one of few fish able to withstand the toxicity of hydrogen sulfide. The high concentration of hydrogen sulfide in the water forces the fish to spend most of their time breathing on the surface, which exposes them to predatory birds; the species has evolved a wave-making behavior to avoid predation.