The limestone salamander. Hydromantes brunus, is a lungless salamander endemic to a portion of the Merced River Canyon in Mariposa County, California. This member of the plethodontidae family breathes through its skin and manifests a flattened body and head. It is typically 5.0 to 7.5 centimeters in length and has webbed toes. The total population of this rare species is estimated at less than 2000 individuals.
The creature's specialized habitat is canyon slopes that are greater than 35 degrees. According to Earth Metrics, the sole Merced River Canyon habitat is part of an area "representative of foothill habitats forming a band along the length of the Sierra Nevada Mountains on the western slopes at intermediate elevations. As a whole, this band is one of the largest contiguous wildlife habitats in the state [of California] A portion of the Merced River Canyon is protected by the State of California and managed by the State Department of Fish and Game as the Limestone Salamander Ecological Reserve