Save the Hellbenders

It was refreshing to find the Appalachian Voice in the mailbox recently; I don't think this small, partisan news magazine has been printed since the hurricane. In this summer's Voice was an article about an animal I've read about but never actually encountered. Since you readers have a high tolerance for biological gross-outs I thought you might like to learn more about the hellbender, Cryptobranchus alleganiensis, which most people never see even if they live near the animals' habitat.

Photo from Tn.gov. 

A hellbender is a sort of salamander. It's not as attractive as more common kinds of salamander. It has a large round head, is the color of clay mud, and can live for thirty years just growing bigger and uglier.  It's usually seen as similar in size and shape to a mudpuppy (it can grow bigger), but lacks the long gills at the back of the mudpuppy's head. Some old hellbenders weigh as much as five pounds, and measure up to 29 inches long; 16 inches long is more typical.

Hellbenders breathe oxygen underwater, through their skins as well as their faces. They can breathe on land but don't venture onto land if they can avoid it. As cold-blooded animals they need to stay where the temperature suits them, which, since they are adapted to function at a much colder body temperature than a warm-blooded animal's, is in deep water. When they swim up to where humans can see them they usually move fast back down to where the water feels good to them. 

Why is it called that? I've often wondered whether "hellbender" was one of those names, like "raccoon" and "skunk" and "possum," derived from an indigenous language. Apparently it's not. Early English immigrants, seeing the animal as some sort of unnatural cross between fish, snake, and lizard, thought it swam fast because it was "hell-bent" on returning to the underworld whence it came. It's also called "snot-otter," if you  prefer. It has no name that Victorians could utter in polite company because people didn't think the animal deserved to be discussed in polite company. Nicknames like "mud dog," "grampus," "den master," and "lasagna sides" are printable but not widely understood. If you want a name that sounds polite, try "cryptobranchid." There is only one species in the genus Cryptobranchus, but if there were others, the family name would be Cryptobranchidae.

Cryptobranchus means "hidden gills." These salamanders have visible gills when they first hatch, but in the second year of their lives the external gills drop off. For the rest of their lives they breathe through bare "gill slits" and absorb oxygen through their skin. 

So why does this animal inspire so much hate? Apparently just because it's big and ugly. It has sharp little teeth and can nip if grabbed; apart from occasional self-defense the animal is a harmless part of the food chain that indicates premium water quality. It stays in the water, eating small fishes and shellfish and doing humans no harm at all. It's not big enough to compete with us for fish big enough to be worth cooking. Though it seems as if it would be a predator on fish--it will eat chunks of killed fish--it's actually a prey animal for fish.

Hellbenders, like loons, can live only where the water is deeper, cleaner, colder, and richer in oxygen than most North American streams have ever been. They're not found in lakes, ponds, or branch creeks where children might wade. 

Their family lives take the concept of patriarchy beyond the wildest dreams of any patriarchal male mammal. Males scoop out nests on the bottoms of rivers. Nests are usually made under rocks or logs, sometimes in holes in riverbanks. Females are allowed in to lay eggs in the nests, where the males fertilize the eggs after they are laid and then defend them until they hatch. Females don't bond with males; they wriggle around together as males try to fertilize eggs as soon as they're laid, but don't have sex in the sense that most animals do. Both sexes are likely to choose another mate the next time. When each female who has mated with a male lays her little round eggs in the same nest, the male may wind up tending a thousand or more eggs, a few hundred from each female. Male hellbenders take their family responsibility very seriously--so much so that they may kill and eat other males who swim too close to their nests. (When not brooding, male hellbenders seem pretty peaceable.) The eggs are about a quarter-inch in diameter and take ten to twelve weeks to hatch. Then the inch-long hatchlings swim away on their own.

Larval hellbenders resemble other baby salamanders. They have noticeable gills for about a year and a half, while they grow to about four inches long, and then they lose the gills and look more like their parents. They breathe through gill slits and through their skins. They have internal structures that are classified as "simple lungs," which they use more for buoyancy than for breathing. A lateral frill of skin on each side, and folds of skin along the body, increase skin surface area and facilitate breathing. In a few more years, when they're six to eight years old and about a foot long, they become able to breed, but they never stop growing.

A baby hellbender with small ear-like gills. Photo from NCWildlife.gov.

They seem to be able to see fairly well in the light, but hunt and eat mostly at night. 

Photo from Wikipedia. Four toes on each fore paw, five on each hind paw.

Appalachian and Ozark hellbenders are different subspecies, but can crossbreed, so they're counted as one species. 

Males and females look alike and are similar in size. Males are more aggressive; they herd gravid females into their nests and keep them there until the females lay their eggs. Females have nothing to do but hide from predators, eat, and wait to grow more eggs and mate again, so they tend to be the individuals who live longest and grow biggest.

There are believed to have been 626 populations of this species. About 40% of those populations have died out. A majority of known surviving populations seem to be declining. States where this animal has been found classify it as "threatened" or "of concerned," and some people lobby for it to be classified as "endangered." 

Threats to the species' existence include

• pollution
• de-oxygenation of river water from pollution, silt, and dams
• loss of river depth as streams silt up, a natural process aggravated by human activities such as ploughing and construction
• anglers catching and killing the animals in the belief that they eat fish and/or are venomous
• fungus and virus infections
• cannibalism when the protective fathers believe the young cannot survive, when an egg seems to be non-viable or when the water becomes muddy

They are a species that nature always intended to remain rare. Populations of hellbenders thin themselves by cannibalism if there is the least chance of overcrowding. 

These unappealing animals caught the Voice reporters' attention when dead bodies of a species many local people had never seen turned up in the aftermath of Hurricane Helene. Many home-loving hellbenders were washed away from their homes to succumb to what they experienced as heat strokes on the mounds of silt and mud displaced by flooding. Though North Carolina's hellbender population was estimated by ones before the hurricane and obviously decimated after the hurricane, living hellbenders have survived and still live in the affected rivers.

Though most people living in the States where they live never have seen a living hellbender and never will, there are things they can do to help this species survive:

1. Preserve stream and river banks, even along shallow branch creeks. Reduce the rate of silt transfer by encouraging large wildflowers, reeds and rushes, and trees where possible, to grow on steep, near-vertical stream banks. 

2. Stop spraying poisons in the outdoor environment. (Poisoning termites inside a building is less likely to affect wildlife.) "Pesticides" kill more valuable wildlife than pests.

3. Try planting crops in mounds of mulch, straw bales, etc., which can even be terraced along hillsides that are too steep to plough, instead of ploughing up topsoil. Mountain people prize "bottom land" that lies at or below the level of the nearest stream because topsoil does not run off every time it rains, and "bottom land" fields are the only ones my family have ploughed since about 1980, but even "bottom land" can still be built up and fertilized with organic mulch.

4. Don't support new construction projects near streams. Especially oppose mining, which adds pollution to the silt it displaces, and large "housing projects" that increase population density and local warming. True Greens already oppose "fracking" and nuclear experiments; hellbenders are just one more species that benefits when humans don't engage in these harmful activities.

5. If you inadvertently catch a hellbender while angling for bass or trawling for catfish, throw it back alive. Handle (or avoid handling) this animal carefully but without fear; it's no more dangerous than a fish of the same size.