Also called such unflattering names as “mud devil,” “devil dog” and “ground puppy,” the hellbender salamander is the largest aquatic salamander in the United States, growing as long as 29 inches, though the average is 12-15 inches. It can be found slowly crawling across the bottoms of clear, silt-free mountain streams from south New York to north Alabama. A separate subspecies, the Ozark hellbender, is confined to a small part of southeast Missouri and northeast Arkansas.
The hellbender is generally nocturnal, spending most of the day under rocks on the riverbed, emerging at night to hunt. Its diet is mostly crayfish, supplemented by small fish, other hellbenders, tadpoles, toads and water snakes. After having covered 30-60 feet and eaten up to 4 crayfish in a night, the salamander returns to its home rock by morning. Adults are extremely territorial, usually chasing off any daytime visitors.
Only occasionally leaving the water, the hellbender makes little use of its lungs. Indeed, one individual survived after having its lungs surgically removed. The salamander absorbs most of its oxygen from the water through its skin, the folds of which maximize surface area. Young hellbenders have gills, which they lose after about 18 months.
Though some populations remain healthy, the hellbender is listed as Near Threatened by the IUCN and is close to qualifying for Vulnerable status, mainly due to habitat loss and degradation. The Ozark Hellbender is particularly imperiled, drastic population declines documented in the late 1980s and 1990s. It is listed as Endangered in Missouri and may soon be listed as Endangered federally.December 10, 2012