What's Hurting Our Hellbenders?

By Jeff Briggler | June 2, 2004
From Missouri Conservationist: Jun 2004

The eastern hellbender (Cryptographs alleganiensis alleganiensis) and the Ozark hellbender (C.a. bishopi) are harmless animals that inhabit Missouri's cold, fast-flowing streams. Once plentiful, their populations are now in peril, and the Missouri Department of Conservation is trying to find out why.

Between 1971 and 1973, researchers observed more than 1,000 hellbenders in the Niangua River. By the 1990s, however, the population had declined by 80 percent. Hellbender numbers in the Big Piney, Gasconade, Eleven Point and North Fork rivers showed similar decreases. Overall, hellbender populations declined by an average of 77 percent.

Equally disturbing is the discovery of many hellbenders with deformities, including missing or malformed legs.

In Missouri, hellbenders can grow up to 2 feet long. People have described them as something only a mother could love. They are reddish-brown and blotchy in color, with wide, flat heads, tiny eyes, short legs, loose skin and a very slimy film over their entire body. The film is a protective coating that decreases friction while swimming. It also is a mild skin irritant to those who come into contact with it.

Hellbenders mostly eat crayfish. They are mainly nocturnal and are seldom encountered. Anglers may catch them on hook and line, however, and giggers might spot them at night with the aid of a light.

Their wide, flat heads make it easy for hellbenders to slip under large, flat rocks on the bottom of fast-moving streams. They usually remain within a home range of less than 70 square yards.

During breeding season in September and early October, female hellbenders deposit between 200 and 700 eggs in a clump. All the eggs are attached by a single strand, however, so their egg masses resemble a bunched string of pearls. After being externally fertilized by male hellbenders, the eggs hatch within four to six weeks. The males remain during this time to guard them.

When the eggs hatch, the larvae that emerge are less than an inch long. During the larval stage, the animals breathe through feathery gills on the side of their head. The larval stage lasts for about two years, during which time a larval hellbender grows to four or five inches long.

At this stage, hellbenders reabsorb their feathery gills and breathe through the many folds of their loose skin. They don't reach sexual maturity until they are about 14 to 15 inches long, which usually takes from five to eight years. Hellbenders may live 55 years in captivity, but in the wild their maximum life expectancy is 30 to 35 years.

Mystery of the Deep

Amulti-agency working group is studying hellbenders to unravel the mystery of their decline. The effort has many components, including captive breeding, survey and monitoring, research and watershed protection.

The St. Louis Zoo and the Mammoth Spring National Fish Hatchery in Arkansas are taking the lead on captive breeding. While young hellbenders produced in captivity may one day be released to the wild, the main purpose of this effort is to preserve genetic stock in case hellbenders are so depleted from Missouri waters that they cannot recover without assistance.

The eastern hellbender is listed as rare in almost every state within its range. It is being considered for inclusion on the federal list of endangered species. The Ozark hellbender lives only in Missouri and Arkansas. It is already a candidate for federal endangered status. Missouri is the only state with populations of both eastern and Ozark hellbenders. Both subspecies were added to the state endangered list in April 2003.

On any given day during the spring, summer or fall, members of the working group may be seen snorkeling the clear waters of Missouri streams in search of hellbenders. As part of their monitoring and surveying efforts, team members catch, weigh, count and tag hellbenders.

From their efforts, the researchers have discovered a disturbing fact. Not only are there fewer hellbenders overall, but there are proportionally fewer young hellbenders than there were 20 years ago.

Anything that damages hellbender habitat can potentially affect their populations. This includes dams, gravel mining, stream siltation, poor water quality, contaminents in run-off, disease and other factors.

Humans also pose certain threats. People take hellbenders from the wild legally, illegally and accidentally. Scientific collecting was permitted in the past, and many hellbenders were taken for that purpose. They are also illegally taken for the pet trade, and by giggers and anglers.

Gigging hellbenders is against the law. If you see someone gigging hellbenders, report them immediately to your local conservation agent or call Operation Game Thief at (800) 392-1111. You can report violations anonymously, and you may reap a financial reward for cases that are successfully prosecuted.

One problem with diagnosing the plight of hellbenders is that their populations are declining even in streams with relatively stable habitat, such as the Current and Jacks Fork rivers.

The deformities are truly mysterious. There's no indication of injury, which would be the case if predators like otters or minks were responsible. Researchers are taking blood samples to determine if a detectable disease is present and to check for compounds like estrogen, which can be found in run-off contaminated by animal waste. Naturally, the deformities are unsettling. If something in the water is causing this, then it might affect people, too.

The working group hopes to be able to determine if the hellbender is the "canary in the coal mine" for Ozark streams. They want to know whether their decline is part of a natural population cycle, or if it is evidence of serious habitat degradation. It's important to find out whether human activities, including pollution, are causing the decline, and whether the hellbender's decline is reversible.

What You Can Do To Help

You can help the hellbender and the people who are trying to save them.

  • Report hellbender sightings to Jeff Briggler at (573) 522-4115, ext. 3201, or e-mail <jeff.briggler@mdc.mo.gov>. Because they are on the streams at night, giggers probably see more hellbenders than anyone else. If you gig, report how many hellbenders you see.
  • Protect hellbender habitat from disturbance.
  • If you catch a hellbender while fishing, cut the line to release it.
  • Report illegal taking of hellbenders.
  • Join a Stream Team to get involved in habitat protection and water quality monitoring.

Hellbenders have a rightful place in Missouri streams. They are an integral, fascinating and harmless component of a healthy ecosystem. With your help, they may once again flourish in their native waters.

Hellbender Highlights

  • Hellbenders are part of the family known as giant salamanders.The largest specimens in North America are about two and one-half feet long. In Asia,members of this family grow to five feet long.
  • Hellbenders breathe through their skin. The many folds of skin undulate as water flows around the animal. Capillaries near the skin surface capture oxygen from the flowing water.
  • Early references suggest hellbenders were so named because their undulating skin reminded observers of "horrible tortures of the infernal regions." A later reference credits an angler who, upon encountering a hellbender, supposed it to be "a creature from hell where it's bent on returning."
  • Hellbenders have many nicknames, including mud-devils,water-dogs, alligators of the mountains and walking catfish.
  • Hellbenders are not dangerous.They are harmless, unique animals that depend on humans to keep their habitat intact.

This Issue's Staff

Editor - Tom Cwynar
Managing Editor - Bryan Hendricks
Art Director - Ara Clark
Artist - Dave Besenger
Artist - Mark Raithel
Photographer - Jim Rathert
Photographer - Cliff White
Staff Writer - Jim Low
Staff Writer - Joan McKee
Circulation - Laura Scheuler