Hellbender (Cryptobranchus alleganiensis)Contributed by Bob Merz – Saint Louis Zoo
The official endangered species of the State of Missouri is an impressive and secretive salamander that can grow up to two feet long and has a few creative local common names. Some folks call them “Snot Otters,” others call them “Devil Dogs,” Lasagna Sides,” “Grampus,” or “Allegheny Alligators.” Missouri is the only State that is native home range to both subspecies, the Eastern Hellbender and the slightly smaller Ozark Hellbender.
Hellbenders are made for life in the water. They usually do not swim, but they walk on the bottom of streambeds. They have wide flattened heads with tiny eyes, and their slippery, flattened bodies move easily through water and slide under rocks. Their well-developed legs and “oar-like” tail help them walk against the current with little resistance. They have prominent folds of skins on their sides (hence the “Lasagna Sides” moniker) that increase the surface area for oxygen absorption.
These amphibians have natural camouflage. Their skin is brown with black splotches - perfect for blending in with their surroundings and avoiding potential predators.
Hellbenders hunt at night, so they depend on smell and touch to find their prey. And while they have a somewhat varied diet, almost 90 percent of the hellbender's diet consists of crayfish. They also eat small fish, insects, worms, and even other, smaller hellbenders.
Since crayfish play such a large part of their diet, it is important to note that invasive crayfish, introduced by anglers releasing bait, are a problem in Missouri. They can introduce disease and displace native crayfish. The Missouri Department of Conservation (MDC) has an education program to highlight this potential impact on native riparian ecosystems.
Both Ozark and eastern hellbender populations in Missouri have declined more than 70 percent over the past 40 years. A population assessment indicated that all hellbender populations have a high risk of extinction (above 96 percent) over the next 75 years, unless populations are bolstered. Based upon these results, zoo propagation and head-starting were deemed essential to the long-term recovery of hellbenders in Missouri.
The Saint Louis Zoo WildCare Institute’s Ron Goellner Center for Hellbender Conservation began in 2004 to address this critical need. This Center is a collaboration between the Saint Louis Zoo, MDC, and the United States Fish and Wildlife Service.
The Saint Louis Zoo established two outdoor artificial streams, an indoor stream, several indoor stream tables, a quarantine room and three large rooms in the Charles H. Hoessle Herpetarium for the conservation of hellbenders. “Founder animals” from four different river systems representing both subspecies were collected to populate the Hellbender Center. The first ever successful zoo breeding of Ozark hellbenders occurred at the Saint Louis Zoo in 2011, and this success has continued annually. In addition to this reproduction at the Zoo, eggs are collected from the wild and head-started at the facility for both the eastern and Ozark hellbenders. The hellbenders raised at the Zoo are released back into the rivers from which they or their parents came from. Without such intervention, both subspecies would likely go extinct in Missouri.