eastern hellbender (Cryptobranchus alleganiensis alleganiensis)
This is a large aquatic salamander with a flattened head, and stocky body with fleshy folds of skins on its sides, a keeled tail, and powerful limbs. The color is usually chocolate brown with darker marking on the dorsum. The adults reach a total length of 76 cm. The head is very broad and flattened with a wide and very flattened snout. The very small, black eyes are widely separated and placed dorsally. The neck width is as great as or slightly greater than the head. The color in life is from yellow-brown, red-brown, to dark brown with varying numbers of black blotches and spots. Ventrally, they are lighter and sparsely spotted if at all. Mating takes place in late summer. The male excavates and guards a nest in which a female may lay eggs. This species inhabits moderate to fast flowing streams and rivers with large flat rocks. It nests under rocks, logs, and other objects. The hellbender has a protective slime that makes them difficult to handle.
The hellbender is known from the New, Holston, Clinch and Powell river drainages and from 23 separate sites. It is distributed widely in rivers of the Ohio and Tennessee systems. It is known from small to large streams and rivers where cover in the form of flat rocks is available. The water is usually cool and clear and well oxygenated. The highest densities in Missouri were correlated with the number of large shelter rocks. Impoundments, siltation, and pollution probably impact populations. They are found in water that is clear, clean and well oxygenated.
This species is primarily carnivorous, eating primarily crayfish, but also some fish which are often scavenged. They mainly eat at night. Trout are not consumed.