This giant amphibian is generally active at night, when it relies on smell and touch to locate its prey. It feeds on a variety of prey, including fish, smaller salamanders, worms, insects, crayfish and snails: catching them with a rapid sideways snap of the mouth (4) (5). It has an extremely slow metabolism and can go for weeks without eating if necessary (3). During the day it retires beneath rocks (4). Like other amphibians, this salamander has smooth skin rather than scales. The skin acts as a respiratory surface, where oxygen enters the body and carbon dioxide is released (4). This species' large size and lack of gills are thought to confine them to cold, fast flowing water where oxygen is in good supply (4). Reproduction takes place in late August, when hundreds of individuals congregate at nest sites. Males compete viciously, with many dying from injuries. Females lay between 400 and 500 eggs in the nest, held together like a thread of beads (3). Several males fertilise the eggs, and protect them from predators like fish, until they hatch 12-15 weeks later in the early spring (5).