For spending their 160 million years of existence mostly hidden in rivers and streams under rocks, the Eastern and Ozark Hellbenders had done quite well.
But in a matter of a few decades, they are fast disappearing. They are hard to find simply because they like to hide under rocks, but most of the time, they don’t hide there anyway because there are fewer around.
“Not only are we catching significantly fewer animals, we’re not catching small ones like in the past,” says Jeff Briggler, the Missouri state herpetologist.
Hellbenders are aquatic amphibians that are the largest salamander in North America by weight, reaching up to 5 pounds. They average about 20 inches long.
For more than 20 years, the St. Louis Zoo, the Missouri Department of Conservation and other agencies have worked together to turn back the clock and save salamanders, and they believe their work has given salamanders at least another 30 years. Their number has decreased by 70% since 1990.
In August, the zoo and MDC celebrated the milestone of the release into native waters of the 10,000th captive-bred salamander, and have since released hundreds more. They bred their first Ozark hellmasters in captivity in 2011 after a decade of trying.
The zoo has the only facility in the world that keeps and breeds Ozark salamanders, with some universities working on a smaller level with eastern salamanders. Both species, which have slight differences in size and color, are federally protected in Missouri. Missouri is the only state that has both types.
“From a natural history standpoint, they’re one of the most specialized vertebrates on the planet. They’re very exotic, bizarre, and bizarre,” says Justin Elden, the zoo’s curator of herpetology.
They’ve been around for so long that they’re the subject of Ozark and Appalachian folktales, and have acquired nicknames like the Allegheny Alligator, snot otter, mud devil, and grampus.
The nickname “old lasagna sides” comes from the frills on his torso, which allow more surface area to absorb oxygen. They have a tail like a rudder, dark spotted fur, a broad, flat head, and a face, Briggler says, that only a mother could love.
“Once you get to know this animal, they are gentle giants,” says Briggler. “Just from the way they look, they’re ancient animals. You feel like you want to help them.”
A combination of factors have harmed the salamander in the wild, including pollution from rivers, changes in their environment, such as movement of the rocks they like to hide under, disease, and changes in river channels. rivers that make the water move faster or slower.
“They’re a living fossil. They’re basically the same animal now as they were millions of years ago,” Elden says. “But because they are specialists in that very specific type of environment, if something changes, the whole haystack comes crashing down.”
Elden is also director of the St. Louis Zoo WildCare Institute Ron and Karen Goellner Center for Hellbender Conservation. It is a series of four rooms in the basement of the zoo’s herpetarium, as well as two rectangular-shaped pools behind the building. The pools simulate wild streams and serve as breeding grounds.
About 2,000 salamanders in various stages of development, from egg to adult, are being raised at the center now. Autumn is Hellbender breeding season, with males left behind in the nest guarding clutches of eggs they have fertilized until they are ready to hatch.
But in the wild, the eggs and young salamanders are particularly vulnerable. Keepers monitor nesting boxes at the bottom of outdoor pools and gather clutches of fertilized eggs so they can be monitored and reared in the controlled indoor environment.
The concrete nests, sometimes built by Briggler staff as a team building exercise, are about the size and shape of a car muffler.
Autumn is a good time to collect eggs. In late September, Hellbender Guardian Katie Noble donned scuba gear, dove into an outdoor pool, and dove underwater.
She reached into a nesting box and slowly and carefully retrieved the clutch of fertilized eggs, a transparent white gelatinous mass with a tiny yellow Ozark salamander embryo inside each one. She stood up and gently pushed the dough into a large white plastic container.
“She’s got the whole world in her hands,” another caretaker crooned as he gingerly loaded the bowl inside.
Keepers measured and weighed adult male hellbenders guarding the nests. The caretakers named the couple Creed and Teddy. They are characters from the shows “The Office” and “Bob’s Burgers”, which are the names of the outdoor swimming pools.
The zoo has a staff of four full-time salamander keepers, who supervise and care for the young salamanders and their eggs, as well as the water in which they live. Once the eggs are introduced, keepers check on them and constantly circulate water to keep the eggs healthy.
“In the wild, a male would flick his tail over the nest during incubation and development, so we mimicked that here,” says keeper Patty Ihrig-Bueckendorf as she checks on an egg tray in an incubator. One egg hatched prematurely, so she placed the embryo inside a small mesh bag to protect it. It should grow just fine that way, she says.
As they hatch and grow, Hellbenders move to larger tanks. There is river gravel in the bottom of the tanks, as well as pieces of white PVC pipe and white wall tiles; hell masters like to hide inside pipes and under stacked tiles. The keepers dim the lights and try to leave the Hellbenders alone until they are old enough to release into the wild.
Almost all of these eggs will live to adulthood. It took years of research and adjustments to get to this point.
“I like to think of it as a kind of recipe,” says Elden. “You always want to have a good final product. You add a little bit of this this year, a little bit of that last year, you take a little bit of this away. And finally, you get to reproduction.”
They carefully monitor the eggs to make sure they are genetically diverse. They are also released into the same river where they or their parents came from.
A large part of Briggler’s job involves driving to the rivers of southern Missouri, checking nest boxes for eggs and looking for signs of salamanders. He likes to hide, but he thinks that the older ones know him better and know that he is coming. Briggler can tell that they are close to him: he will see a piece of fur floating on the water or see a spot on the sandy river bottom where a Hellbender had rested on his chin.
Briggler sees hopeful signs. In 2006, he found the first clutch of eggs from him. A year later, he found five. This year, he found a record number: 18.
“We bought this animal a lot more time,” he says. “The trajectory looks much better.”
Elden sees the Hellbenders as great advocates for promoting the health of ecosystems and streams and the conservation of Missouri’s species.
“We have been living alongside them for thousands of years, as long as Native Americans have been in the United States,” he said.
“I want to make sure they’re always around for people. Even if they don’t see them, they know they’re there.”
(c) 2022 the St. Louis Post-Dispatch
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Citation: Helping Hellbenders: St. Louis experts work to breed struggling species (November 21, 2022) Retrieved November 21, 2022 from https://phys.org/news/2022-11-hellbenders -st-louis-experts-struggling.html
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