Wee hellbenders. Courtesy of the St. Louis Zoo.
They're huge, kinda freaky-looking, and on their way back.
They're Ozark hellbenders—snot otters if you're nasty—endangered river salamanders that grow up to two feet long and live in Missouri's river systems. Wild hellbender populations have been in decline for decades, under attack from human causes like pollution and destruction of their natural habitat. The amphibians need cool, clean running water to breed and grow, and since scientists from the Missouri Department of Conservation began studying their populations back in the late '80s, they noticed declines of 70 to 80 percent.
Now, after a decade-long collaboration between the Missouri Department of Conservation and the Saint Louis Zoo, the first Ozark hellbenders have been bred in captivity—an encouraging sign for the threatened creatures.
"This is, for me, in my 24 years in the zoo field, the most exciting thing I've been a part of," says Jeff Ettling, curator of herpetology and aquatics and director of the Ron Goellner Center for Hellbender Conservation at the Saint Louis Zoo.
In mid-November, the world's first fully captive-bred Ozark hellbenders started hatching at the zoo.
Female hellbenders have been successfully laying eggs in the zoo's habitat since 2007. Despite careful efforts to reproduce the Ozark river ecosystem, sperm wasn't getting through to the eggs. Eventually, scientists discovered that it was the ion content of the water was stopping them. So the carefully pH-calibrated water, flowing in very specific methods with mocked-up rain and light cycles, was tweaked once more. The sperm got moving, and the babies were bred.
They began life as a clutch of eggs under a rock in an artificially-created outdoor river at the zoo, being guarded by their proud papa, who externally fertilized them after a female laid them. The male stood guard over the course of seven weeks, until the eggs hatched. (In the wild, he'd be keeping away predators as well as other adult male hellbenders, who might eat them.) Then, for the next 45 to 60 days, they'll keep their yolk sacs for nourishment. They'll grow legs and lose their external gills by the time they're a year and a half to two years old. In the wild, a large portion of the young wouldn't make it to adulthood. Hellbender larvae make lovely snacks for crayfish, water snakes and cottonmouths. Plenty of them would succumb to fungus or chemical contamination, as well.
Once they reach adulthood, the salamanders can live for decades. Their legs make it easy for them to move against river currents. And while running across a two-foot-long salamander might scare the hell out of you on a float trip, it's important to note that they're harmless to humans.
Hellbenders are an important part of the Missouri and Arkansas ecosystem, Ettling says. They keep the populations of tasty fish and crayfish under control by feeding on them. In addition, they're important bio-indicators—if hellbenders, with their slick and highly-sensitive skin, aren't doing well, it says that the whole surrounding system is in trouble. (For instance, studies have show that men living around rivers with steady hellbender declines have lower sperm counts.)
And with any creature that's part of an ecological web, there's always an X-factor, an unknown but important role it could be playing.
"We don't really know what happens when you take anything out of nature," Ettling says. "Everything has its position."
While the hatchlings are the big news, of course, they are the result of a decade-long collaboration between the Zoo and the Department of Conservation that has had plenty of success already. In 2002, the Department of Conservation collected eggs from the wild, which were then "head-started" at the zoo, raised in a controlled, predator-free environment and fitted with radio transmitters. After six years, 36 of them had reached maturity, and were released into the North Fork of the White River, where about three-quarters of them survived.
"That was a very encouraging sign to all of us," says Ettling. "If we can bring a portion of those eggs in and bring them up for six to eight years, that gives them a fighting chance."
Ettling says the Zoo and the Department of Conservation hope to continue breeding Ozark hellbenders and releasing them into the wild, ultimately reversing the decline of the ancient species. He says it's at least 20 more years of work.
"I think for us, having it be something right in our own backyard makes it more important—to be able to show the people of Missouri that we're not ignoring our own backyard."
