Eastern Hellbender
Cryptobranchus alleganiensis
Eastern hellbenders are the largest salamander species in all of North America! They are aquatic salamanders and spend all of their time in fast flowing streams. Even though they do have lungs, eastern hellbenders actually get most of their oxygen through the many folds of skin on the sides of their body. These salamanders usually make their nests under flat rocks and are considered ambush predators since they will wait for prey to get near their nest before lunging for it. Not only are they great at capturing prey, but they also have special defenses against their own predators. In fact, eastern hellbenders have a layer of slimy, bad tasting mucus covering their body that protects them from parasites as well as predators.
Credit: J Hutton
SPECIES IN DETAIL
Eastern Hellbender
Cryptobranchus alleganiensis
CONSERVATION STATUS: Near threatened
CLIMATE CHANGE: Vulnerable
At the Aquarium
Not currently displayed.
Geographic Distribution
Found through much of the Appalachian mountains, from Southern New York to Northern Georgia. Solitary and found at the bottom of streams.
Habitat
Fast-flowing streams and rivers, preferably clean, clear, and well-oxygenated. They live in parts of the stream that are shallow in depth and have many large, flat rocks, logs, or boards for nesting sites and cover.
Physical Characteristics
Usually brown/gray-ish brown in color with darker or lighter colored blotches on their backs. They can also range from yellowish brown to almost black. Their bellies are lighter in color and are occasionally sparsely spotted. Flattened head and body with a rudder-like tail. Small, widely separated dark eyes with four short legs.
Juveniles have external gills that they lose when they are around 4-5 inches long (18 months old)
Size
30-74 centimeters (12-29 inches), up to 4 lbs.
Males and females are similar in size, though males may be a little heavier and broader.
Diet
About 90% of their diet consists of crayfish, but they will also eat small bottom dwelling fish. As juveniles, they have been seen to consume a variety of invertebrates. They will occasionally eat other hellbenders and hellbender eggs.
Reproduction
External Fertilization – Males release their sperm over a clutch of eggs (~200-400) that a female has laid in a cluster of long strands under a large, flat rock, or in an opening in bedrock.
Females reach sexual maturity around 7-8 years in age whereas males can breed at a slightly younger age.
After fertilization, males guard the eggs for 4-6 weeks until the eggs hatch.
Behavior
Eastern hellbenders are solitary animals that stay in a small range close to their nest. They will sit and wait for prey to come close to their hiding spot under a flat surface, and crawl along the bottom of streams. They are nocturnal animals, meaning that they are more active and hunt at night.
Adaptation
Eastern hellbenders are adapted to live and breathe in clean and fast-flowing water through the use of many capillary-filled folds of skin on the side of their body. Their lungs are thought to be used for buoyancy control. Their flattened body allows for less resistance against the river and stream currents. They have developed a layer of slimy, bad tasting mucus covering the body that protects against parasites and predators.
Longevity
Under natural river conditions, hellbenders live around 30-35 years. In captivity, they can live over 50 years.
Conservation
Because eastern hellbenders breathe through their skin, pollution, warming waters, and other changes to the streams have negatively impacted these animals. For example, damming and channeling of waterways has caused these once fast-flowing streams to become slow. As a consequence, we have seen a drastic decline in the eastern hellbender population over the last few decades as well as a decline in the amount of young hellbenders that reach maturity.
While the International Union for Conservation and Nature has not listed the eastern hellbender as endangered, many states have given them protective status. Many institutions are trying to help restore the Hellbender population such as the Ron Goellner Center for Hellbender Conservation at the St. Louis Zoo whose goal is to create a zoo breeding program for successfully rearing Hellbender larvae to sexual maturity.
Special Notes
The eastern hellbender is the largest salamander in North America.
- Their bodies are covered in a thin mucus layer that helps protect them from parasites and predators.
- They are also called by nicknames such as “snot otters,” “devil dogs,” “mud dogs”
- The males are the ones that actually guard the nest of eggs until they hatch
- They are an excellent indicator of good quality water as they prefer clean streams and rivers.
Last Updated: June 18, 2024
SPECIES IN DETAIL | Print full entry
Eastern Hellbender
Cryptobranchus alleganiensis
CONSERVATION STATUS: Near threatened
CLIMATE CHANGE: Vulnerable
Not currently displayed.
Found through much of the Appalachian mountains, from Southern New York to Northern Georgia. Solitary and found at the bottom of streams.
Fast-flowing streams and rivers, preferably clean, clear, and well-oxygenated. They live in parts of the stream that are shallow in depth and have many large, flat rocks, logs, or boards for nesting sites and cover.
Usually brown/gray-ish brown in color with darker or lighter colored blotches on their backs. They can also range from yellowish brown to almost black. Their bellies are lighter in color and are occasionally sparsely spotted. Flattened head and body with a rudder-like tail. Small, widely separated dark eyes with four short legs.
Juveniles have external gills that they lose when they are around 4-5 inches long (18 months old)
30-74 centimeters (12-29 inches), up to 4 lbs.
Males and females are similar in size, though males may be a little heavier and broader.
About 90% of their diet consists of crayfish, but they will also eat small bottom dwelling fish. As juveniles, they have been seen to consume a variety of invertebrates. They will occasionally eat other hellbenders and hellbender eggs.
External Fertilization – Males release their sperm over a clutch of eggs (~200-400) that a female has laid in a cluster of long strands under a large, flat rock, or in an opening in bedrock.
Females reach sexual maturity around 7-8 years in age whereas males can breed at a slightly younger age.
After fertilization, males guard the eggs for 4-6 weeks until the eggs hatch.
Eastern hellbenders are solitary animals that stay in a small range close to their nest. They will sit and wait for prey to come close to their hiding spot under a flat surface, and crawl along the bottom of streams. They are nocturnal animals, meaning that they are more active and hunt at night.
Eastern hellbenders are adapted to live and breathe in clean and fast-flowing water through the use of many capillary-filled folds of skin on the side of their body. Their lungs are thought to be used for buoyancy control. Their flattened body allows for less resistance against the river and stream currents. They have developed a layer of slimy, bad tasting mucus covering the body that protects against parasites and predators.
Under natural river conditions, hellbenders live around 30-35 years. In captivity, they can live over 50 years.
Because eastern hellbenders breathe through their skin, pollution, warming waters, and other changes to the streams have negatively impacted these animals. For example, damming and channeling of waterways has caused these once fast-flowing streams to become slow. As a consequence, we have seen a drastic decline in the eastern hellbender population over the last few decades as well as a decline in the amount of young hellbenders that reach maturity.
While the International Union for Conservation and Nature has not listed the eastern hellbender as endangered, many states have given them protective status. Many institutions are trying to help restore the Hellbender population such as the Ron Goellner Center for Hellbender Conservation at the St. Louis Zoo whose goal is to create a zoo breeding program for successfully rearing Hellbender larvae to sexual maturity.
The eastern hellbender is the largest salamander in North America.
- Their bodies are covered in a thin mucus layer that helps protect them from parasites and predators.
- They are also called by nicknames such as “snot otters,” “devil dogs,” “mud dogs”
- The males are the ones that actually guard the nest of eggs until they hatch
- They are an excellent indicator of good quality water as they prefer clean streams and rivers.
Last Updated: June 18, 2024