Scientists Are Releasing the Lovingly Nicknamed ‘Snot Otters’ Into Ohio Waterways in a Big Success for Conservation Eastern hellbenders, the largest amphibians in North America, are in trouble, but conservationists are hard at work to help the wrinkled wonders survive Sarah Kuta - Daily Correspondent November 10, 2025 11:20 a.m. Eastern hellbenders are known as "snot otters" because they're covered in a slimy, protective coating. Grahm S. Jones / Columbus Zoo and Aquarium Eastern hellbenders (Cryptobranchus alleganiensis) are unusual creatures. These elusive amphibians can grow up to two feet long, making them the largest salamanders in North America. They breathe exclusively through their wrinkly skin, and are covered in a slimy, protective goo that has earned them the nickname “snot otter.” They’re also in trouble. Their numbers are declining throughout much of their range in the eastern United States, and federal officials say they’ve already gone extinct in some areas. This summer, however, the species got a boost when biologists let loose 116 juveniles into protected waterways in eastern Ohio. Fun Fact: Hellbender or mudpuppy? Despite a distinctive look and name, Eastern hellbenders can easily be confused with another colorfully-named American river salamander, the mudpuppy. Here's how to distinguish the two, per Purdue University's "Help the Hellbender" project: Hellbenders lack gills as adults and have wrinkles, unliked their smooth, gilled counterparts. The release, announced in early October, was part of a state-wide recovery effort called the Ohio Hellbender Partnership, involving the Columbus Zoo and Aquarium, The Wilds, the Ohio Department of Natural Resources, Ohio State University and other collaborators. Since 2012, the partners have reintroduced more than 2,000 captive-raised eastern hellbenders in Ohio—and, so far, their work seems to be paying off. In 2023, researchers discovered that the lab-reared critters were reproducing in the wild, a milestone that has them feeling more optimistic about the species’ future in the state. “This is quiet work that adds up,” says Greg Lipps, a conservation biologist at Columbus Zoo and Aquarium working on the project, in the statement. “One stream, one release, one more sign that clean water and wildlife can thrive together in our community.” Researchers released more than 100 eastern hellbenders in Ohio this summer. Grahm S. Jones / Columbus Zoo and Aquarium As part of the project, researchers also recently installed 30 additional “hellbender huts,” adding to the more than 100 they’ve already positioned in Ohio’s waterways. These manmade dwellings, crafted from concrete, give the salamanders safe places to hide out and lay their eggs. They also make it easier for scientists to keep tabs on the animals and their offspring, according to the zoo, even when the water is murky. While placing the new structures, researchers discovered that eastern hellbenders had taken up residence in 19 of the pre-existing huts. The salamanders even laid eggs in two of them. In addition, scientists gathered more than 2,000 eggs from three nests, some of which are being used to help the creatures rebound in neighboring Indiana. Eastern hellbender recovery efforts hinge primarily on a conservation technique known as “headstarting,” in which biologists temporarily raise young animals in captivity before releasing them into the wild. This approach is meant to give animals a “head start” on life, since they’re protected from predators and disease when they are at their youngest and most vulnerable. Scientists have used headstarting to help the large salamanders for more than a decade. They gather eggs from the species’ native range, bring them back to a lab and hand-rear the juveniles until they’re robust enough to survive in rivers and streams. They tag the youngsters to keep an eye on them after they’ve been released. Eastern hellbenders need fresh, clear water to thrive, so the work also involves partners focused on cleaning up Ohio’s waterways. The salamanders are an indicator species, meaning their numbers can serve as a proxy for environmental health. Healthy eastern hellbender populations mean healthy streams—good news for lots of other animals, including humans. Researchers have long known that habitat issues are driving the species’ decline. Recently, a Kentucky-based team zeroed in on sedimentation—the accumulation of fine sediment—as a major environmental threat. Mud Devil, Allegheny Alligator, Water Dog, Walking Catfish, Old Lasagna Sides, Snot Otter ... In a study published in August in the journal Freshwater Ecology, scientists explain how fine sediment like silt and grain fills in the crevices beneath rocks where eastern hellbenders like to lay their eggs. It also packs the small spaces that larvae use for shelter. The researchers say the findings provide a straightforward, environmental roadmap for conservationists who want to help the eastern hellbenders make a comeback. “First, keep sediment out of streams,” says study co-author Steven Price, an ecologist at the University of Kentucky, in a statement. “Then protect and rebuild rocky beds and forested streambanks. That’s how we give this species a chance.” Get the latest stories in your inbox every weekday.

Eastern hellbenders, the largest amphibians in North America, are in trouble, but conservationists are hard at work to help the wrinkled wonders survive