LITTLE ROCK, Ark. — The four-legged Ozark hellbender is big and not very pretty.
It's also very uncommon, prompting the U.S. Fish and Wildlife Service to suggest the freshwater salamander be added to the nation's endangered species list.
The Ozark hellbender lives only in southern Missouri and northern Arkansas, the agency says. The animals can grow up to 2 feet long and once were common in the streams of the Ozark Mountains, but their numbers have greatly dwindled.
"Not everyone considers it pretty, but it is a pretty neat animal," said Fish and Wildlife Service biologist Trisha Crabill in a recorded interview produced by her agency.
Crabill, who works in the agency's field office at Columbia, said the Ozark hellbender is not well known because the salamander has dark, mottled skin and is not often seen.
"Most people won't ever see them because they stay pretty well hidden in the water," she said. "They don't ever really come out of the water and they're found just in the pools of fast-flowing streams in the Ozark Plateau."
Crabill said siltation in the Ozarks streams, as well as increased levels of nitrogen and phosphate from fertilizers and contamination by human and animal waste, has helped reduce the species' numbers. She said higher nitrogen and phosphate levels have led to algae and other vegetation that clog the streams and coat the rocks of the streambeds.
Other factors, she said, had been heavy metals in the water, such as zinc and lead from mining-operation runoff. The Ozarks region was once mined heavily for both metals.
According to Crabill, the karst terrain of the Ozarks — with underlying limestone allowing water to make its way easily from place to place underground — makes controlling pollution difficult in the region.
"There's a lot of water falling underground through sink holes, caverns and other openings that have been created by the rocks dissolving underground," she said.
Collette Adkins Giese, a lawyer for the Center for Biological Diversity, said the proposed endangered-species listing of the Ozark hellbender is cause for celebration. Protection under the Endangered Species Act, she said, "would give this species a fighting chance."
According to a news release from the center, the Ozark hellbender is a subspecies of the Eastern hellbender.
The large amphibians are known by several common names, including alligator of the mountains, big water lizard, devil dog, ground puppy, leverian water newt, mud-devil, vulgo, walking catfish, and water dog.
The release said hellbenders have flattened bodies that fit in crevices and allow them to cling to river bottoms and move through strong currents. They also have numerous folds of skin on their sides that allow increased oxygen absorption from the water.
The Fish and Wildlife Service says the salamanders are believed to occur now in only six Arkansas counties — Baxter, Clay, Fulton, Lawrence, Randolph and Sharp — and 11 in Missouri — Carter, Dent, Douglas, Howell, Oregon, Ozark, Reynolds, Ripley, Shannon, Texas and Wright.