The Ozark hellbender (Cryptobranchus alleganiensis bishopi) is a subspecies of the hellbender (Cryptobranchus alleganiensis), strictly native to the mountain streams of the Ozark Plateau in southern Missouri and northern Arkansas. Their nicknames include lasagna lizard and snot otter. These large salamanders grow to average from 29-57 centimeters in length over a lifespan of 30 years. Ozark hellbenders are nocturnal predators that reside under large flat rocks and primarily consume crayfish and small fish. As of 2011, the U.S. Fish and Wildlife Service (USFWS) has listed the subspecies as endangered under the Endangered Species Act of 1973. The species population decline is caused by habitat destruction and modification, overutilization, disease and predation, and low reproductive rates. Conservation programs have been put in place to help protect the species.