Creature Feature: Hellbenders

Hellbenders are one of the more curious wildlife denizens of the national park system. Photo by Jeff Humphries

Despite their curious name, “hellbenders” are not demons of the night but rather amphibious environmental monitors of Southeastern creeks and streams. Known to some old-timers as “walking catfish,” these super-sized salamanders gained the “hellbender” moniker for their freakish size and dark, moody color.

A mature hellbender is generally mud-green or grey-colored with dark splotches, weighs about four pounds, and has a flat, paddle-shaped body. Fleshy folds of skin that run the length of the salamander's side are one of the amphibian’s more interesting characteristics. These flaps increase the surface area of the hellbender’s skin to allow more oxygen into their lungs when submerged, which is basically all of their lives.

Hellbenders generally live in the area drained by the Ohio and Tennessee rivers. Very few have ever been found in watersheds that drain to the Atlantic, and none west of Arkansas.

The amphibians, which don’t start reproducing until age 7 and can live about 30 years in the wild, are found in the cool, rocky streams of the southern Appalachians. While Great Smoky Mountains National Park is probably the easiest place to fine one, you can get lucky at New River Gorge National River, Shenandoah National Park, or any other Appalachian park. In the Midwest, Ozark National Scenic Riverways is your best bet for spying one of these elusive creatures.

As much as two-and-a-half feet in length at adulthood, hellbenders feast on crawdads, small fish, and other invertebrates. Though most active at night, they will sometimes come out from underneath their rocks during an overcast day. The salamander, which has few natural predators other than birds, will hibernate to a degree during the winter, digging a nest in the mud.

Not much is known about the species' background. Some evidence inconclusively points to Chinese and Japanese salamanders as possible relatives. But Native Americans were known to eat the hellbender, so scientists are relatively certain that the species was not introduced from overseas. There are two subspecies, an Ozark Hellbender and an Eastern Hellbender, but some scientists have called for a review of this and are suggesting that the Ozark population isn't a subspecies. Instead, they believe the two populations are the same animal, but geographically and genetically isolated from each other

The enormous salamander's powerful tails, beady eyes, and broad head are perfectly adapted for the swift waters of the Appalachians. While it is not particularly venomous, the hellbender does secrete a slightly toxic slime to reduce friction and has a powerful jaw. Because of this, it gained a reputation among sportsmen as being a viscous fish killer that would ruin a good trout stream by gobbling down all the sport fish. Things were so bad that during the early 1900s a bounty was imposed on the critters, and the population – particularly in the Ozarks – is thought to have plummeted (based on how many are known to have been brought in for money).

Ironically, though, hellbenders are one of the best indicators of a healthy river, as they prefer to live in well-oxygenated, pristine waters. Starting around the 1970s, states began to list the salamander as threatened, but it has little widespread federal protection.

In a 1996 study in the Susquehanna River watershed, every hellbender caught and tagged was judged to be at least 25 years old. The scientists concluded that since the average age of the hellbender was high, there must be an incredibly low reproduction rate, which could mean significant species decline. However, scientists don't know for sure what the historic population levels were to begin with.

Threats to the salamander run the gamut of the usual river issues – siltation (having too much dirt in a river to the point that it's more mud than anything else), agricultural runoff, low dissolved oxygen levels, and dams all disturb the hellbender.

Conservation efforts over the past few years have done much in the eastern half of their range to restore the aquatic habitat that these remarkable animals need to survive. While the Ozark subspecies is thought to be bordering on extinction, the Eastern hellbenders of the Smokies and Blue Ridge mountains are on the upswing, thanks to increased protection, habitat restoration, and public education.

With hopes of bolstering the Ozark population, the St. Louis Zoo has partnered with the U.S. Fish and Wildlife Service's Mammoth Spring National Fish Hatchery in Arkansas to breed hellbenders for release into the wild, and the Missouri government has assembled a research team to compile a comprehensive study of the hellbenders.

Hellbenders are sometimes accidentally caught by anglers. If you happen to catch a hellbender, gently remove the hook and release it back into the water. You are encouraged to report any sighting of a hellbender to the nearest wildlife management agency, as population levels are only guesstimates. Moreover, if you see anyone harming a hellbender, you should report it to local law enforcement immediately.

Hopefully, with continued preservation efforts both in and out of our national parks, the hellbender will continue to cling to survival. While it isn’t likely to become a poster child for the parks (owing to its bizarre appearance), it is one of the park system's many treasures.

Comments

There has been much discussion about the overuse and abuse of the Spring River in and around Mammoth Spring.
The decline of the Hellbender is taken very seriously by a lot of residents in the area.

The start of the decline of the Hellbender seems to be caused (perhaps, maybe?) by the introduction of trout into the river.
Check the dates of initial trout release and the studies of Hellbender population and you too can see a correlation.

It has been suggested by myself that an area of one mile below dam three be designated as a Hellbender habitat, and that no trout be released, and no large scale canoeing launches from resorts be allowed in the area.

The raising of Hellbenders for release into the wild cannot logically take place if the river is not wild.

In the meantime release Hellbenders further down stream concurrently, simutaneouly and then you will have a real study, and a chance of reviving the species in the wild.

Chance, I am so happy to see the start of this new article. As a youngster I was always looking for any and all animals. I am really going to enjoy reading these articles and reliving some of my youth! To explore and find animals was always my favorite thing to do. Just ask your mother!

Love ya lots....

In southern Missouri, the scientists and others fighting to protect the Ozark hellbender are not just battling against habitat loss, water pollution, and overcollection. According to an article in the Spring 2008 issue of Defenders, researchers recently found that some of the Ozark hellbenders are infected with the deadly chytrid fungus (Batrachochytrium dendrobatidis, aka "Bd"). This discovery must have made them feel about the way you would feel if you found a timbler rattler in your baby's crib. Just how bad is the chytrid fungus? Scientists say that the organism, an invader that apparently originated in Africa, can kill up to 80% of the amphibians it infects. Since amphibians are part of a very complex web of life, chytrid-initiated population crashes have the potential to cause a great deal of ecosystem disruption. It remains to be seen whether and when scientists will come up with methods for reducing or eliminating the chytrid fungus threat. Meanwhile, pessimists say that the only sure way to have healthy populations of hellbenders, frogs, and other amphibians in the chytrid-affected areas is to scoop up some still-healthy amphibians, put them in biosecure facilities, and return them to the wild after the chytrid firestorm has burned itself out. This is certainly not a good time to be a hellbender.

Trout have been stocked in hellbender streams since the late 1800s and certainly by the 1920s. Although the stocking of trout has increased along with the decline of hellbenders in some areas of Missouri, the populations have been hit by a plethora of issues in that same time period. Collection events during the late 70s and early 80s have wiped out over half of a well studied population. There has been disease, habitat destruction, pollution, siltation, etc.

There certainly is a correlation with stocking introductions, but that doesn't mean it has caused the issue.

Just some information regarding the origins of the hellbender.

Hellbenders are in the family Cryptobranchidae which is a very old group of salamanders (considered a prototype). They have found Cryptobranchus salamander fossils in China recently from over 140 million years ago. The giant hellbenders from Japan and Asia are also in this family but in a different genus (Andrias). Hellbenders were not introduced over here from Asia, they are just relatives.

Asia and the eastern US have many similar species and it has to do with the movement of the continents. Many years ago Asia and the US were connected and many species were shared. The areas split apart and still shared similar species. However, in the western US the Rocky Mountains sprang up and changed the climate and environment of the entire western US thereby limiting many of the species in the US to the eastern range. Then the species between Asia and the US were apart for a long enough period that the animals became different species. There has been a lot of genetic work which can even show distinct groups within the hellbenders in the US!

Also, it is still unknown whether reproduction is low or the larvae are difficult to find in some areas. They were never really captured in the first place in many places, so its hard to know!

Anyway, great article! Thanks for letting people know about the wonderful hellbender!