Boulder Darter (Etheostoma wapiti)

Description: 

The Boulder Darter is a federally endangered species restricted to a single river system in the middle Tennessee River drainage. They have recently been introduced to a second small river system. As the common name suggests, they live in fast riffles with large rocks in small to medium rivers. Like many other members of the subgenus Nothonotus, Boulder Darters have a moderately pointed snout.