Nature Lab

Each month, we highlight research MDC uses to improve fish, forest, and wildlife management.

Resource Science: Hellbender Recovery

 “Hellbender” is the common name for Cryptobranchus alleganiensis, a large, seldom-seen aquatic salamander native to the rocky, cold-water streams of the Ozark Highlands.

“Hellbenders have dramatically declined over the past 40 years in Missouri, with a prominent shift in age structure towards large, mature individuals with young age-classes virtually absent,” said Missouri State Herpetologist Jeff Briggler. “Historic population estimates were over 45,000 animals. Today less than 2,300 are known from the wild in Missouri.”

Briggler said a multitude of factors have likely influenced hellbender populations. Chief among these are habitat alteration and degradation, disease, illegal harvest and disturbance, and predation. “Declines are likely due to a cumulative effect of these factors,” Briggler said.

In order to slow the hellbender’s decline and address the potential threats facing this animal in Missouri, Briggler and other partners are leading recovery efforts. His partners include researchers, state and federal agencies, the Saint Louis Zoo, and private citizens.

Some of the recovery team’s most significant progress has involved breeding and rearing young hellbenders at the Saint Louis Zoo and an MDC hatchery.

“Consistent captive-breeding of the species for six consecutive years at the Saint Louis Zoo and rearing of young obtained from eggs collected from the wild has resulted in over 5,000 animals released back into their native river,” Briggler said.

Captive-breeding achievements will not only buy time for the team to further address the species’ decline, but they will likely be the safety net needed to save this unique native species of the cold-water streams of the Ozark Highlands.

Hellbenders at a Glance

• Historic population and range in Missouri - Estimated at over 45,000 in rocky Ozark streams, but less than 2,300 remain.
• Their role in Ozark stream ecosystems -  Predator, mainly of crayfish. Prey of larger fish, and some mammals.
• How they breathe - Numerous fleshy folds along the sides of the body provide surface area for respiration under water.
• How long they live -  25–30 years in the wild.
• Reproductive age - 5–8 years, and males normally mature at a smaller size and younger age than females.
• Who guards the eggs and larvae - Male hellbenders protect eggs and recently hatched larvae from predation.