The hellbender salamander is the largest variety of the salamander in North America, as well as the third-largest in the world. It can live to be 30 years old or more in the wild, and can survive 50 years in captivity.
Hellbenders can be found in rivers and streams around the eastern United States. Throughout the 16 Eastern states in which the animal is normally seen, populations are in a steep decline. Some marine biologists are concerned these losses could reflect a general decline in environmental conditions.
Hellbender salamanders breathe nearly exclusively by extracting oxygen from water, using their skin in respiration. Because of this, many biologists believe the animals might serve as an early-warning signal, set off by pollution in their native environment.
"Because of their preference for clean streams and rivers, hellbenders serve as indicators of stream health. The presence of young and adults is synonymous with good water quality," the Virginia Department of Game and Inland Fisheries wrote on its Web site.
The nocturnal amphibians prowl through the shallow water, seeking out worms, minnows, snails and other small prey. Afterward, they head to swiftly-flowing water and nest under large, flat logs, stones, and debris to rest for the day.
Population losses of salamanders could be attributed to their preference for particular locations. Locales featuring swift, shallow waters are becoming less common in the states where the animals are becoming rarer. Where they do still exist, many of the environments are becoming polluted.
"Untreated sewage, sedimentation, and chemical runoff from lawns, fields, and parking lots all contribute to a reduction in their populations. Because respiration is through the skin, any toxic substance in the water can have significant adverse health effects," the department reported.
Hellbender salamanders possess a long, rough, slimy body, earning the species the unflattering nickname of the snot otter. They can grow to be two feet in length or more. Partly due to its beady eyes, some people call the animals devil dogs or mud devils. No one is certain of the origin of the name hellbender.
Help the hellbender is a movement, sponsored by Purdue University, aimed at protecting the species. Its Web site provides information for anglers and outdoor enthusiasts who spot the species in the wild, as well as tips to avoid polluting habitats of the animals.
Suggestions for homeowners include the creation of rain gardens, which help collect rainwater, feeding plants that love a moisture-rich environment. They also encourage people to build green roofs -- large gardens that mostly, or entirely, cover flat roofs.
The Ozark hellbender was added to the national endangered species list in 2011. The U.S. Fish and Wildlife Service is now considering adding the eastern hellbender to that list.