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10 Slimy Facts About Hellbenders

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North America’s biggest salamander is a reclusive crayfish-eater with a compressed body and some rather unflattering nicknames.


Hellbenders have exacting real estate needs. Suited for a very specific habitat, they can only be found in clear, fast-moving streams with large, flat rocks at the bottom. An adult male hellbender will usually defend a territory of about 1000 square feet that is centered around its favorite rock—under which the animal sleeps.


There’s just one recognized species of hellbender, which scientists have dubbed Cryptobranchus alleganiensis. Wild ones may be encountered as far north as New York State, as far south as Alabama, and as far west as Missouri.

The hellbender grows up to 29 inches long, making it earth’s third-largest salamander. Number one is the appropriately-named Chinese giant salamander (Andrias davidianus). Exceeding even some humans in size, this Asian monster can reach 5.9 feet in length and weigh 110 pounds. Right across the Sea of Japan lives the Japanese giant salamander (Andrias japonicus), which grows to be about 5 feet long and maxes out at around 55 pounds.

Together, these three juggernauts form the Cryptobranchidae family. Fossils reveal that the group once invaded Europe and western North America. The hellbender’s ancestors most likely evolved in Asia before migrating to the U.S. via land bridge.


“Hellbender” is an intense name for such a harmless amphibian. How did this word come about? Nobody knows. Perhaps—as herpetologist C.M. Bogert once wrote—early settlers thought that the animal looked like “a creature from hell where [it was] bent on returning.” Or maybe its wrinkled skin reminded someone of the tortures said to take place in Satan’s domain. Both theories seem plausible.

Hellbenders have gone by other nicknames as well, including devil dogs, mud-devils, lasagna lizards, and Allegheny alligators. Yet another nickname refers to their texture: Grasping a hellbender is quite difficult because of the slimy mucus that coats its skin, so they're sometimes known as snot otters.


Though they also feed on insects, earthworms, and small fish, crayfish represent 90 percent of a hellbender’s natural diet. Upon gulping one down, the salamander uses sharp, tiny teeth to pierce its shell. (These chompers can also break human skin.)


USFWSmidwest, Flickr // CC BY 2.0

There are some unfortunate hellbender myths floating around out there. For instance, fishermen have long accused them of driving away bass and other game fish by eating their eggs—or even the fish themselves. However, scientists have yet to find any such foodstuff inside of a hellbender’s stomach [PDF].

Another common misconception is that the salamanders have venomous fangs. People who believe this often kill them on sight—even though this accusation has no merit. In fact, no one has yet discovered any amphibian with such a bite.


Like many amphibians, these stream-dwellers primarily breathe through their skin, extracting oxygen from water. This process is made easier thanks to folds running along their sides, which increase the skin’s surface area.

Hellbenders do have lungs, but they definitely aren’t vital organs. Consider this: As part of a 1967 experiment, both lungs were surgically removed from one individual [PDF]. The animal survived, and its ability to process oxygen was unaffected by the ordeal. So does this mean that a hellbender’s lungs are useless? Not quite. They may not be used for respiration, but the organs probably help regulate buoyancy underwater.


Nighttime is when these creatures do most of their hunting. Between dawn and dusk, hellbenders can usually be found hiding under rocks. On cloudy days, however, they tend to get a bit more active and may leave their haunts well before nightfall [PDF].

Come mating season, the amphibians get particularly bold. Most hellbenders reproduce in either August or September. During those months, they’re far more likely to be active in broad daylight—especially before noon.


A male prepares to breed by digging a tunnel under some nearby rock. Once finished, he curls up inside and pokes his head out. Ideally, a passing female will spot him and swim on over. The male then guides her into the hole, where she’ll release anywhere from 150 to 450 eggs. As she lays them, he sprays semen all over the clutch, fertilizing it.

Following this, the male chases his mate away and proceeds to spend the next few weeks protecting their unborn offspring. Ordinarily, hatching takes place somewhere between 64 and 80 days later. By then, there’s a good chance that the father will have eaten a few of the eggs—though never more than 20 or 30.


Brian Gratwicke, Flickr // CC BY 2.0

If placed ashore by some disruptive human, hellbenders can crawl back into the river, but unlike many amphibians, they almost never leave the water voluntarily. In the water, the salamanders mainly get around by crawling over submerged rocks—though the animals are decent swimmers as well.


Two subspecies are out there—and they’re both in trouble. The Ozark hellbender (Cryptobranchus alleganiensis bishopi), native to southern Missouri and northern Arkansas, has grown frighteningly scarce. Recent estimates indicate that there may be as few as 590 individuals left in the wild. Since the 1980s, the Ozark hellbender population has gone down by roughly 75 percent.

Elsewhere, the eastern hellbender (Cryptobranchus alleganiensis alleganiensis) isn’t faring much better. Previously widespread throughout their New York State range, they now exist in only a few streams and rivers. Similar reports have been made about the animal’s fading presence in West Virginia, Tennessee, Missouri, and Georgia [PDF].

Why are these creatures dying out? Siltation is the main culprit. Whenever a forest is torn down, huge amounts of soil and sand are disturbed. These later get washed into nearby waterways—including the streams that hellbenders call home. Unwelcome sediments muddy up their habitat, bury their tunnels, and suffocate their eggs.

Still, hope remains. Zoos from Toledo to St. Louis have launched captive breeding programs designed to lend snot otters a helping hand. If all goes well, these efforts will rejuvenate our ailing hellbender populations with a surge of young, healthy sub-adults. Keep your fingers crossed.

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Owning a Dog May Add Years to Your Life, Study Shows
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We've said that having a furry friend can reduce depression, promote better sleep, and encourage more exercise. Now, research has indicated that caring for a canine might actually extend your lifespan.

Previous studies have shown that dog owners have an innate sense of comfort and increased well-being. A new paper published in Scientific Reports and conducted by Uppsala University in Sweden looked at the health records of 3.4 million of the country's residents. These records typically include personal data like marital status and whether the individual owns a pet. Researchers got additional insight from a national dog registry providing ownership information. According to the study, those with a dog for a housemate were less likely to die from cardiovascular disease or any other cause during the study's 12-year duration.

The study included adults 40 to 80 years old, with a mean age of 57. Researchers found that dogs were a positive predictor in health, particularly among singles. Those who had one were 33 percent less likely to die early than those who did not. Authors didn't conclude the exact reason behind the correlation: It could be active people are more likely to own dogs, that dogs promoted more activity, or that psychological factors like lowered incidences of depression might bolster overall well-being. Either way, having a pooch in your life could mean living a longer one.

[h/t Bloomberg]

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Big Questions
Why Don't We Eat Turkey Tails?
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Turkey sandwiches. Turkey soup. Roasted turkey. This year, Americans will consume roughly 245 million birds, with 46 million being prepared and presented on Thanksgiving. What we don’t eat will be repurposed into leftovers.

But there’s one part of the turkey that virtually no family will have on their table: the tail.

Despite our country’s obsession with fattening, dissecting, and searing turkeys, we almost inevitably pass up the fat-infused rear portion. According to Michael Carolan, professor of sociology and associate dean for research at the College for Liberal Arts at Colorado State University, that may have something to do with how Americans have traditionally perceived turkeys. Consumption was rare prior to World War II. When the birds were readily available, there was no demand for the tail because it had never been offered in the first place.

"Tails did and do not fit into what has become our culinary fascination with white meat," Carolan tells Mental Floss. "But also from a marketing [and] processor standpoint, if the consumer was just going to throw the tail away, or will not miss it if it was omitted, [suppliers] saw an opportunity to make additional money."

Indeed, the fact that Americans didn't have a taste for tail didn't prevent the poultry industry from moving on. Tails were being routed to Pacific Island consumers in the 1950s. Rich in protein and fat—a turkey tail is really a gland that produces oil used for grooming—suppliers were able to make use of the unwanted portion. And once consumers were exposed to it, they couldn't get enough.

“By 2007,” according to Carolan, “the average Samoan was consuming more than 44 pounds of turkey tails every year.” Perhaps not coincidentally, Samoans also have alarmingly high obesity rates of 75 percent. In an effort to stave off contributing factors, importing tails to the Islands was banned from 2007 until 2013, when it was argued that doing so violated World Trade Organization rules.

With tradition going hand-in-hand with commerce, poultry suppliers don’t really have a reason to try and change domestic consumer appetites for the tails. In preparing his research into the missing treat, Carolan says he had to search high and low before finally finding a source of tails at a Whole Foods that was about to discard them. "[You] can't expect the food to be accepted if people can't even find the piece!"

Unless the meat industry mounts a major campaign to shift American tastes, Thanksgiving will once again be filled with turkeys missing one of their juicier body parts.

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