The eastern hellbender hails as America's largest aquatic salamander.
It is grey to olive brown.
The Eastern Hellbender is totally aquatic. They breath through folds in their skin. The gills stay in their neck, but are not used. The hellbender goes through incomplete metamorphis. The lungs are used only for buoyancy. They can get up to 29 inches in size. The young lose their gill slits at 4 or 5 inches. These external gills make it very difficult for the salamander to survive anywhere but in constantly flowing water.
Born with external gills and gill slits, a hellbender will not undergo the metamorphosis stage of losing its external gills for 18 months; this is one of the longest larval periods (that eventually produce a metamorphic change) of any American species of salamander.
Hellbenders can live to be 55 years old.
The Eastern Hellbender is totally carnivorous. The diet consists primarily of crayfish but insects, fish, and worms will also be eaten (Behler and King 1979). The hellbender has a very unique mechanism for capturing and consuming its prey. It exhibits a highly unusual mode of asymmetrical suction feeding in which the bilateral elements of the mandibles and hyoid move independently. Typically the hellbender only depresses one side of the mandible, dropping the jaw 10 to 40 degrees from the resting position and the prey is drawn in with a jet of water (Pough et al. 1998).
Aquatic salamanders such as the eastern hellbender have their ear bone attached to their lower jaw bone, and when they touch their lower jaw to the stream bottom vibrations are picked up and transmitted to the ear bone.
"the hellbender belongs to the suborder Cryptobranchoidea which is the most primitive of the living salamanders and may hold clues for scientists to use when studying the evolution of other salamanders" (Cogger and Zweifel 1998).
Hellbenders are aquatic organisms throughout their life and remain active year-round. These salamanders generally spend the daylight hours in a natural or self-excavated den beneath large slabs of rock or other shelter-providing objects (logs and boards) on the bottom of streams or rivers.
Acid Mine Drainage threat
Agricultural runoff and the acidic runoff from large scale mining operations threaten much of
the hellbenders habitat. (Danch 1996).
It has disappeared from a large portion of its range due to silting and pollution of streams.
The number of hellbenders has been reduced over the century because of acid mine drainage, industrial pollution, and excessive siltation.
The hellbender subsists primarily on crayfish, and no longer thrives in streams and rivers where pollution has destroyed crayfish populations.
Available evidence does suggest that numbers of these salamanders have declined and there is little evidence of successful reproduction recently.
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