Hellbender – Giant Salamander of North America
What does a hellbender look like?
Hellbenders are very long, measuring 12 to 29 inches. Their color ranges from drab brown to olive brown, with irregular black marks scattered on their backs and tails; their undersides are lighter, ranging from light brown to yellowish-orange. Hellbenders are soft and fleshy—their skins seem too loose for their bodies. Their bodies are somewhat flat, especially at the head, and the mouth is large with small, sharp teeth on both jaws. A smaller set of double crescent-shaped teeth are found on the roof of the mouth. The eyes are small, beady and unlidded.
How did it get its name?
Few people are even aware of the hellbender’s existence, and those who do know it often mistake it for a small alligator. They are also often called “waterdogs” or “mud puppies.” Hellbenders have obviously been associated with some very unpleasant experiences—it may be that early fishermen believed that hellbenders were creatures from the underworld who were “bent” on returning to that place.
What is the hellbender’s preferred habitat?
Hellbenders are found in cold, fast-moving streams and rivers from southern and western New York down to northern Georgia, Alabama, and Mississippi, and as far west as central Missouri and possibly southeastern Kansas. The eastern hellbender is found throughout most of this range, while the Ozark hellbender is found only in southeastern Missouri and northeastern Arkansas. In North Carolina, hellbenders are found only in the mountains of the state’s western region.
How is the hellbender adapted for its habitat?
The hellbender is well-adapted for life in fast-moving streams. The powerful tail and webbed feet described above allow them to move efficiently through waterways. Also, a set of horizontal flaps of skin along the sides of their bodies allow hellbenders to extract oxygen directly from the water. When water levels are low, adults can rise to the water’s surface and simply gulp air through their mouths. Recently hatched and juvenile hellbenders, though, have feathery red gills that they use for underwater breathing.
What do hellbenders eat?
Hellbenders primarily eat crayfish, but will also eat aquatic invertebrates, small fish and (perhaps) fish eggs. They can also be scavengers, eating anything that has died in the water. The will also eat other hellbenders or unguarded hellbender eggs.
How do hellbenders reproduce?
Hellbenders breed in late summer or early fall. A male hellbender will use his tail to scoop out a nest depression under a large rock or other debris in a quiet part of the waterway. The male then attracts one or more females to the depression; the females release eggs and the male fertilizes them.
Nests may contain 300 to 400 eggs if a single female is involved, or as many as 1000 eggs if several females are involved. The eggs may be eaten by the male or a female, but they are usually regurgitated and then develop normally.
Females are forced from the nest site soon after the eggs are laid. The male guards the eggs from crayfish and other predators by laying with his head near the opening of the nest site. He will move air over the eggs during the entire 8- to 12-week incubation period.
When they hatch, hellbender larvae are about 1.5 inches long, with undeveloped legs and large heads. After a few months the legs form fully; after two or three years they lose their gills. Maturity is reached between five and eight years of age.
What threats to hellbenders face?
Hellbenders are very vulnerable to water pollution. High amounts of silt in streams—which can occur due to highway construction, home building, or other activities causing erosion—quickly affect hellbenders. Other pollution from industrial and urban communities also threatens the animal.
Acid draining from mines is also a problem for hellbenders, as is the construction of dams, reservoirs and other structures that slow the speed of streams and allow impurities to build up in the waterways. Also, canoe rental facilities have begun using dynamite to remove rocks and boulders from streams in order to make it easier for their canoes to pass. This probably increases the amount of sand and silt in the stream, which in turn harms the hellbenders; many hellbenders have been found with deep cuts in their heads and bodies that appear to be related to heavy canoe traffic.
Finally, the practice of “gigging” for hellbenders, especially popular in the Ozark Mountains, is causing damage since the gigging season coincides with the hellbender’s reproduction season.
Is the hellbender an endangered species?
In general—and especially in the southern range of the species—hellbenders have active and viable populations, though they do receive some special protection in some states. In these southern areas, though, it is the ecosystem in which the species lives, and not the species itself, that receives special protections.
Why should the hellbender be protected?
The hellbender is an important part of stream and river ecology. For example, they help control crayfish populations, which is helpful to fishermen because crayfish often feed on the eggs of gamefish. Also, hellbenders help remove diseased or weak individuals from the larger fish population.
Most importantly, though, hellbenders are an excellent “indicator species.” This means that they very accurately reflect the overall health of an area’s streams and rivers. When hellbender populations begin to decline in that area, it is a good sign that the entire ecosystem is degraded as well, and is in need of increased protection. Even though the hellbender is only one member of the river and stream ecosystem, it is like a “canary in a mineshaft” and can tell us much about the quality of that system.
See other Hellbender articles…
Hellbenders are Federally listed as a “species of concern” and may be a candidate for listing as an endangered species. Human impacts like acid mine drainage, dam construction, siltation from farms, forestry, and housing development... Read More
Hellbender research has shown steep declines—some as high as 77 percent—among a few hellbender populations. The Appalachian population in the southeastern United States in particular has received little scientific attention. This may be because many... Read More