Tuxedo Darter (Etheostoma lemniscatum)

Description: 

The Tuxedo Darter is a federally endangered species that is currently restricted to the Big South Fork of the Cumberland River Drainage in northern Tennessee and southern Kentucky. They live near the banks of creeks, primarily in pools with gravel substrate. Like other members of the subgenus Catonotus, this species spawns on the underside of flat rocks. In this group, males of some species have knobs on their first dorsal fin that are hypothesized to serve as an “egg-mimic” to attract females for spawning.