The Ozarks are a physiographic and geologic highland region of the central United States. It covers much of the southern half of Missouri and an extensive portion of northwestern and north central Arkansas. The region also extends westward into northeastern Oklahoma and extreme southeastern Kansas. The hellbender, North America’s largest amphibian, was named one of the 10 U.S. species most threatened by freshwater pollution in a report released today by the Endangered Species Coalition. The report, Water Woes: How Dams, Diversions, Dirty Water and Drought Put America’s Wildlife at Risk, highlights how reductions in water quality and quantity threaten imperiled species in 10 important ecosystems across the country. The Ozark hellbender, which can grow longer than two feet, is found in streams in northern Arkansas and southern Missouri. The eastern hellbender ranges from Mississippi to New York. Both have declined in recent years and remain threatened with extinction due to water pollution and dams.
The hellbender (Cryptobranchus alleganiensis), also known as the hellbender salamander, is a species of giant salamander that is endemic to eastern North America. These salamanders are much larger than any others in their endemic range, they employ an unusual means of respiration (which involves cutaneous gas exchange through capillaries found in their dorsoventral folds), and they fill a particular niche—both as a predator and prey—in their ecosystem which either they or their ancestors have occupied for around 65 million years.
"Hellbenders are strange and fascinating creatures that also serve as a barometer for the health of the freshwater systems where they live," said Collette Adkins Giese, an attorney at the Center for Biological Diversity who works to protect amphibians and reptiles. "When we protect water quality for hellbenders, we also protect water that people rely on for drinking, fishing and recreation."
The Ozark hellbender has declined by 75 percent since the 1980s, with fewer than 600 remaining in the wild. The primary threat facing Ozark hellbenders is degradation of their aquatic habitats from sources such as mining, fertilizer runoff and animal operations. The eastern hellbender has declined by at least 30 percent. Hellbenders are fully aquatic salamanders, meaning they never leave the water. In highly polluted waters they develop dramatic skin lesions.
The Ozark hellbender was protected under the Endangered Species Act in 2011 as part of an agreement with the Center for Biological Diversity to speed protection decisions for 757 imperiled species across the country. The eastern hellbender is under consideration for protection in response to a petition filed by the Center in 2010 seeking protection for hundreds of at-risk freshwater species in the southeastern United States.
Hellbenders, ancient animals that have changed very little over time, are uniquely adapted to aquatic life. They have paddle-like tails for swimming and flattened bodies and heads that fit in crevices and allow them to cling to the river bottom. Numerous folds of skin on their sides allow increased oxygen absorption from the water. They have lidless eyes and largely rely on vibrations and scents for communication and foraging. They secrete toxic slime to ward off predators but are not poisonous to humans. Hellbenders forage at night, preying on crayfish, insects, dead fish and other amphibians, and are in turn eaten by fish, turtles and snakes. Males build nests by making saucer-shaped depressions in gravel and then defend their nests until young are about three weeks old. Hellbenders reach sexual maturity at 5 to 8 years and may live as long as 30 years.
For further information see Endangered.
Hellbender image via Wikipedia.