Few Americans realize that the United States is home to a GIANT, ancient salamander that has roamed the earth since the time of the dinosaurs. Scientists call this creature a hellbender, but it has many colorful names: devil dog, Allegheny alligator, old lasagna sides, hogfish, and (my favorite) snot otter. At nearly 2 ½ feet long, hellbenders are part of a family of giant salamanders (known as Cryptobranchids) that first appeared in central Asia over 160 million years ago. As you’ve surely guessed by the nicknames, it is not an attractive creature (at least not by Homo sapiens’ arbitrary standards). With a brown, flat, slimy, wrinkled body, hellbenders aren’t winning any beauty contests. But they ARE exquisitely bizarre and unlike anything else in the western hemisphere.
Legend has it that an ugly, wrinkled salamander escaped from “hell” and was “bent” on getting back – hence the unfortunate name. Unlike most salamanders, hellbenders spend their entire lives underwater and can live for more than 50 years. Despite being called “repulsive” in the scientific literature (a distinction shared by very few species), hellbenders are marvelously adapted to life at the stream bottom. With miniscule eyes atop its wide head, the hellbender is so flat that it almost appears two-dimensional. This peculiar body type works well for an animal that spends about 90 percent of its time squished under big, flat rocks. Hunting at night, hellbenders rely on a keen sense of smell to detect an unsuspecting fish or crawdad. Their broad, flat mouth opens in an instant to form a gaping oval that devours the prey whole. And that prey can be a quarter of the size of the hellbender itself – that’s like the average American eating a 50 pound meal in less than a minute! So if you ever encounter a hellbender, make sure it’s had a chance to digest before picking it up (unless you’re dying to know what fish carcass smells like).
If its size, lifespan, body shape, and evolutionary history weren’t impressive enough, what truly distinguishes the hellbender from other salamanders is its bizarre approach to breathing (or respiration). Hellbenders have one of the most inefficient respiratory systems in the animal kingdom. Not only do they breathe water (which has about 30 times less available oxygen versus air), but they have completely given up on gills. That’s right; a hellbender loses its gills when it’s about a year old. Instead, oxygen slowly diffuses through the salamander’s skin, directly into its bloodstream. And if that weren’t bizarre enough, hellbenders have very simple lungs that they don’t use to breathe. These air sacs serve as a flotation device, allowing the hellbender to rise or fall effortlessly in the water (similar to a fish’s swim bladder). Determined to make its odd breathing strategy work, the hellbender has evolved deeply-wrinkled skin that is packed with blood vessels. Wrinkles equate to more skin, which means more opportunity for oxygen to reach the blood vessels. And to top it all off, hellbenders have developed an “oxygen dance” – a sideways rocking behavior that helps keep the water around their skin fresh and highly oxygenated.
As the only Cryptobranchids left on Earth, the hellbender and its two cousins (the Chinese and the Japanese giant salamanders) represent three lonely branches in a 160 million-year-old family tree. And the tree isn’t looking healthy. These salamanders are rapidly disappearing, due to a toxic mix of pollution, development, and poaching. In the U.S., many streams are becoming contaminated with sediment (or mud) from nearby tree-clearing and development, suffocating any resident hellbenders. Deforestation and low flow rates (which can result from large water withdrawals) heat up the stream, making it difficult for hellbenders to breathe, because water holds less oxygen as it warms. Even hellbenders that live in clear, pristine streams may be needlessly killed by fishermen (or anyone spending time in the river) who mistakenly believe that they are poisonous. On the contrary, hellbenders are not poisonous, aggressive, or dangerous. But although the species faces some serious threats, there’s reason for hope. Hellbenders are still thriving in some areas, and a growing number of Americans are catching “hellbender fever” (defined as the sudden, uncontrollable urge to help protect hellbender salamanders). The closely-related Japanese Giant Salamander (which can grow 5 feet long) is a familiar and beloved symbol of national pride in Japan. Just imagine the clout the hellbender would have if we had the gumption to name it the American Giant Salamander. But in the end, it doesn’t really matter what you call it – a devil dog, hogfish, or snot otter. A hellbender by any other name is just as neat.
Click here to learn what you can do to help the hellbender.
This blog written for the U.S. Department of State’s Our Planet blog. See the post in its natural habitat here.