Rough-skinned Newt

The rough-skinned newt is native to the Pacific coast of North America, ranging from southern Alaska to central California, generally in moist forest habitat and the ponds and slow streams it breeds in. It is dark brown above with a granular, rough-textured skin, contrasting sharply with a bright orange-yellow belly that it displays by arching its body when threatened. Its skin produces tetrodotoxin, one of the most potent toxins known in nature, at levels in some populations high enough to kill most vertebrate predators many times over. The species is the central figure in a well-studied evolutionary arms race with common garter snakes, some populations of which have evolved genetic resistance to the toxin, driving the newt's populations toward ever-higher toxicity in a coevolutionary escalation documented across the Pacific Northwest.