The Eastern hellbender–also called a snot otter, devil dog, mud dog, grampus, or Allegheny alligator–is one of the world’s largest species of salamander. The animal, formally Cryptobranchus alleganiensis, has been declining and is officially listed as “near threatened” by the International Union for the Conservation of Nature.
Much larger than any other salamanders in their range, hellbenders are most closely related to giant Japanese and Chinese salamanders (which can grow up to six feet long). Hellbenders’ flat bodies average about two feet (60 centimeters) in length, but have been known to reach lengths up to 30 inches (74 centimeters).
Hellbenders feed on crayfish and small fish in rocky, swift-flowing rivers in a host of Eastern states. They have an unusual means of respiration that involves gas exchange through capillaries found in their dorsoventral folds.
This week, the Wildlife Conservation Society’s Bronx Zoo announced that it re-introduced 38 of the rare animals into streams in western New York. The animals had small chips embedded in their skin for future tracking.
The “hellbender head-start program” is a collaboration between the Bronx Zoo, the New York State Department of Environmental Conservation, and the Buffalo Zoo. The snot otters were hatched at the Buffalo Zoo in October 2009 and raised at the Bronx Zoo’s Amphibian Propagation Center.
In a statement, Patricia Riexinger, director of the Division of Fish, Wildlife and Marine Resources at the New York State Department of Environmental Conservation, said:
The hellbender is an important part of our state’s aquatic biodiversity and it’s clear that we have to take dramatic steps to ensure its continued presence in New York. Numerous studies over the past decade have shown that there are few young hellbenders available to join the breeding population. This ‘head-starting’ program will enable us to release young hellbenders back to the wild at a life-stage that may enable them to survive and thrive in New York. We deeply appreciate the support of WCS, the Bronx Zoo and the Buffalo Zoo as conservation partners in the recovery of this iconic salamander.
In New York, the hellbender is listed as a species of Special Concern. As in much of their range, the giant salamander has declined there thanks to disease, pollution, and loss of habitat.
Not many people have seen a hellbender in the wild, because they are fully aquatic and like to hide under large rocks. They have a distinctive appearance, with tiny eyes and wrinkly sin. They are usually brown or reddish-brown, with a pale underbelly.
The narrow edge along the dorsal surface of their tails helps propel them through the water, according to the Bronx Zoo.
As to how the salamander got that distinctive name, the Missouri Department of Conservation says:
The name ‘hellbender’ probably comes from the animal’s odd look. Perhaps it was named by settlers who thought “it was a creature from hell where it’s bent on returning”. Another rendition says the undulating skin of a hellbender reminded observers of “horrible tortures of the infernal regions.” In reality, it’s a harmless aquatic salamander.
Brian Clark Howard covers the environment for National Geographic. He previously served as an editor for TheDailyGreen.com and E/The Environmental Magazine, and has written for Popular Science, TheAtlantic.com, FastCompany.com, PopularMechanics.com, Yahoo!, MSN, and elsewhere. He is the co-author of six books, including Geothermal HVAC, Green Lighting, Build Your Own Small Wind Power System, and Rock Your Ugly Christmas Sweater.