Hell-bent on Survival
On a chilly spring day in 2003, Cathy Jachowski was wading shin-deep in a North Carolina stream when she came face-to-face with a giant, wriggling mass of brown slime. It was exactly what she was looking for—the elusive hellbender.
A recent college graduate, Jachowski had been working as an itinerant science educator when a grad student hired her for fieldwork. Part of the job involved surveying promising creek beds for hellbenders, large aquatic salamanders native to North America. As she struggled to stay upright on the slippery stones in rushing water, Jachowski watched the graduate student lift a rock in the creek. Moments later, a foot-and-a-half-long salamander was sitting in a net.
It was dark brown and flat, and its feet ended in little pink toes that helped it grip the streambed. Its mouth was large, its skin fell in wrinkly folds, and it was covered from head to toe in a layer of mucus. Jachowski was hooked.
“A lot of people would probably say, ‘That sounds terrifying, why would you go near it?’” Jachowski says. But, despite their ominous-sounding name and prehistoric appearance, hellbenders are harmless.
They’re also vanishing. Once common in streams and rivers right in our backyards, hellbenders have been hit by a triple threat: illegal pet traders, diseases like the amphibian chytrid fungus, and warming habitats polluted by sediment and runoff.
The U.S. Fish and Wildlife Service added one subspecies, the Ozark hellbender (Cryptobranchus alleganiensis bishopi), to the endangered list in 2011 and is currently evaluating the other, the Eastern hellbender (Cryptobranchus alleganiensis alleganiensis). In 2006, scientists estimated that there were only 590 Ozark hellbenders left in the wild, although current estimates are closer to 1,200. But Jeff Briggler, Missouri’s state herpetologist, cautions that this increase doesn’t necessarily mean the population has grown—it just means that scientists like him have gotten better at surveying it.
More than a dozen years after she saw her first hellbender, Jachowski is now a graduate student at Virginia Tech and part of a small community of scientists dedicated to understanding and protecting these strange animals—which have earned the nicknames snot otters, old lasagna sides, and even grampus. (“I think it comes from grandpa, because they’re so wrinkly,” says Kimberly Terrell, a hellbender biologist at the Memphis Zoo.)
The stakes for saving the snot otter are higher than simply preserving a single species. Hellbenders are so sensitive to water quality that when they start disappearing, other creatures that depend on clean water are at risk as well.
“They represent what we think of as an umbrella species,” Jachowski says. “If we take care of the hellbenders, we’re taking care of a whole lot of other species at the same time.”
“If we take care of the hellbenders, we’re taking care of a whole lot of other species at the same time.”
Hellbenders, along with their relatives the Japanese giant salamander and the Chinese giant salamander, are part of an ancient lineage that dates back to at least 160 million years ago. The hellbender’s ancestors likely originated in Asia and migrated to North America via a land bridge. Millions of years later, these salamanders have adapted to life in the cool, flowing streams of the Ozarks and watersheds in the Eastern United States.
In late summer through early winter, male hellbenders locate suitable rock dens and allow one or more females to lay clutches of hundreds of eggs inside. Sometimes, the eggs aren’t even in a den. Max Nickerson, who has studied hellbenders since 1968, remembers finding eggs scattered across a stream bed, and females trailing strands of eggs behind them. “I grabbed one of those females and she regurgitated eggs,” says Nickerson, herpetology curator at the Florida Museum of Natural History. “She was eating eggs and laying eggs at the same time.” It was, he recalls, “kind of wild.”
Once the females have laid their eggs, the males fertilize them. Then they guard the nest against potential predators, including other hellbenders, for around two months until the eggs hatch. The males then may keep watch for several months more, until the hatchlings are developed enough to leave the den.
These giant amphibians, which look, says Nickerson, “like someone stepped on them,” live for approximately 30 years in the wild and eventually can grow to two feet long and up to five pounds—mainly by staying sedentary and eating a diet of crayfish, aquatic insects, small fish, hellbender eggs, and other hellbenders. To catch their prey, they open their mouths quickly enough to generate a vacuum that sucks the meal inside.
Although hellbenders have lungs and are born with gills, they actually breathe through their skin. They reabsorb their gills by around age two and seem to use their lungs for buoyancy rather than for breathing. This helps to explain their wrinkly appearance: the folds and frills of flesh maximize the hellbenders’ oxygen-absorbing surface area.
“Virtually everything about them is kind of bizarre, and interesting, and different from a biological perspective,” Terrell says. “I also think it’s pretty incredible to think about this animal that comes from a family that’s been on Earth for tens of millions of years.”
But their environments are changing—and it’s not clear whether the hellbenders will be able to adapt. Sediment eroding into watersheds threatens to fill the spaces between stones and gravel on river bottoms where hellbenders hide, lay eggs, and find food. As streams warm, the water’s oxygen-carrying capacity decreases, making it harder for the salamanders to absorb enough oxygen. Finally, Ozark hellbenders are suffering from infections of mysterious origin. And then there’s the illegal pet trade—enough of a concern that scientists don’t like to reveal the salamanders’ exact locations. All told across the hellbender’s range, pockets of the two subspecies have decreased by over 80 percent. The Ozark subspecies is in more immediate danger because it lives in a more restricted habitat.
Still, Terrell is optimistic about the hellbender’s prospects. “There’s definitely a growing number of people out there who are interested and are trying to do what they can to ensure the species’ survival,” she says. “I think they’ve got a fighting chance.”
Skin Breathing 101
Hellbenders’ tiny lungs provide very little of the oxygen the animals need to survive.
They take in oxygen and release carbon dioxide—the gas exchange we think of as breathing—directly through their skin. Two important adaptations make this possible.
First, extra skin, which forms wrinkles along the salamanders’ sides, increases surface area.
Hellbenders position themselves in fast moving currents to ensure the flow of. oxygen-rich water across these folds.
Second, their skin is rich with capillaries positioned close to the surface. Gas passes directly through the blood vessel walls by diffusion.
Oxygen flows from higher concentrations in the water to lowe concentrations in the blood, while carbon dioxide does the opposite, flowing from higher concentrations in the blood to lower concentrations in the water.
For both Eastern and Ozark hellbenders, population declines have hit younger animals particularly hard, and it’s not clear why. Scientists at the St. Louis Zoo are trying two approaches to boost wild populations’ numbers: captive breeding and a head-start program in which fertilized eggs are collected from the wild and safely reared in captivity past their most vulnerable stages.
Successfully breeding hellbenders was a decade-long quest that included building massive streams within the St. Louis Zoo and tweaking the water’s ion concentrations to match those in the hellbenders’ home rivers. In 2011, the zoo’s efforts finally paid off with the first successful hellbender captive breeding. Since then, researchers have released over 2,700 hellbenders–raised from both captive-bred and wild-caught eggs– into the wild. An additional 4,000 that they reared live at the zoo.
Collecting eggs in the wild isn’t easy either—but Jeff Briggler, a herpetologist employed by the Missouri Department of Conservation, has developed a system using artificial nest boxes.
Briggler vividly remembers his first success. On a sunny day in November 2010, he and a colleague snorkeled through a Missouri river’s 56°F water, checking seven concrete nest boxes that they’d buried in the riverbed six months earlier. They found nothing until Briggler reached the sixth box—and a male Ozark hellbender popped his flat head out and bit down on Briggler’s camera.
When Briggler opened the lid of the box and peered inside, he saw more than a hundred eggs in the bottom, their yellow yolk sacs—what Briggler calls his “golden nuggets”—gleaming back at him. At that point, very few nests had been found in Missouri.
Briggler scooped out the eggs with a net, transferred them to an aerated bucket, wedged the bucket in the backseat of his car, and cranked up the air conditioning. Then he carefully drove his cargo to the Shepherd of the Hills Hatchery in Branson, Missouri—pulling over several times to make sure the eggs were still okay.
They were carrying something, he says, “that was worth its weight in gold in our minds. This was precious cargo.”
The young hellbenders reared from those first nestbox eggs were released back into the wild in the summers of 2014 and 2015. In the last five years, Briggler has expanded the program to more than 80 boxes he checks each fall. And Cathy Jachowski, Briggler’s former employee, has set up nest boxes of her own in Virginia’s rivers—so she can peek inside to learn about the hellbenders’ breeding behavior.
Briggler says efforts like these give him hope that the hellbender might survive.
“Back in the mid-2000s, I would be asked, ‘Do you think you can save this animal from extinction in your state?’” Briggler recalls. “And I would be brutally honest—I did not think we could. Being asked that question now, I totally believe we can.”
Illustrations by Erna Kristin Mendez
Frequently donning a mask and snorkel to access his photographic subjects, David Herasimtschuk’s passion lies in producing imagery that helps foster a greater appreciation for the hidden life beneath the surface of our rivers and streams. By working with Freshwaters Illustrated, a non-profit that uses film and photography to create awareness of freshwater conservation issues, Herasimtschuk aims to create imagery that not only captures the public's imagination, but also helps motivate a new discourse in the way we value rivers.