Hoosier Cavefish (Amblyopsis hoosieri)

Completely blind, this hardy fish thrives in the dark environment of caves. Its range is restricted to a few dozen cave streams north of the Ohio River and south of the East Fork of the White River. Because of this restricted habitat, the Hoosier Cavefish is listed as an endangered species. Unlike surface fish, this cavefish lacks pigmentation — its pinkish color is due to the hemoglobin in its blood.

The Hoosier Cavefish received a great deal of press when State Road 37 was widened to four lanes between Bedford and Mitchell, Indiana. Several fish were found in a passage opened by construction, and were released in nearby Bluespring Caverns. The alarm that went through the environmental community eventually resulted in a Memorandum of Understanding between the Indiana Dept of Transportation and several other state agencies to help ensure that future road work is performed in a more karst- friendly manner.

Closely related to the Northern Cavefish found in Mammoth Cave, the Hoosier Cavefish was not recognized as a separate species until 2014. Photo courtesy Wikimedia Commons