IT LOOKS like it has crawled out of a stinking primeval swamp, or as if it’s bound for some unspeakable gothic underworld. But the hellbender (not to be confused with the rock band, computer game or jeep) is no monster: it’s one of the world’s largest aquatic salamanders, hiding under rocks in fast-flowing, winding streams in remote parts of the US. When it does venture out, though, Cryptobranchus alleganiensis has a very mixed relationship with people, winning lots of fans and enemies.
So what exactly is the fascination? Hellbenders grow up to 75 centimetres long and look like giant, flattened tadpoles with severe bathtub wrinkles. These wrinkles increase the skin’s surface area and therefore the space available for capillaries below the skin, through which the hellbender breathes. The fleshy folds make the salamanders feel slimy because of the mildly toxic mucus they generate to protect their skin from pathogens and deter predators. The mucus wins the hellbender another endearing nickname – snot otter.
“Its mildly toxic mucus wins it the nickname of snot otter”
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In the 1920s, anglers thought they destroyed trout fisheries and put 25 cent bounties on their heads. Far from using those unsightly jaws and their tiny teeth to eat trout, however, hellbenders grab crayfish and swallow them whole. They also tuck into other hellbenders’ eggs when short of food, and even, occasionally, swallow each other up.
Ironically, although this unlovely occasional cannibal looks like it should live in a swamp, its presence indicates a clean river: skin-breathing animals are very vulnerable to pollution. By keeping crayfish under control, they also improve river biodiversity.
But deteriorating water quality, the number of dams and the anglers’ spite has got the giant salamander onto the endangered species lists in some US states, with populations declining an average 77 per cent since the 1970s. Once widely distributed throughout the Appalachian mountains and the Midwest to the Ozark mountains of Arkansas and Missouri, hellbenders are now mainly confined to the Appalachians.
Another, surprising factor in their decline, says the journal Applied Herpetology, is the number removed from streams to be sold as pets.
Pets? While it’s illegal to keep them in the US, hellbenders are secretly shipped to south-east Asia, turning up in pet stores in China and Japan. With more people chasing the “next big thing” in exotic, rare animals, the critters can fetch up to $1700 in Japan.
This is bad news. Hellbenders are particularly vulnerable to overcollection because they live a long 30 years and their young have low survival rates. The good news for our hellish friends is the Wilds conservation centre in south-east Ohio, which is working to improve their numbers. The centre is building an artificial stream, complete with just the right windiness and water flow to make hellbenders feel at home enough to breed in well-managed captivity.
Endangered species – Learn more about the conservation battle in our comprehensive special report.
