Egg-mimic Darter (Etheostoma pseudovulatum)

Description: 

The Egg-mimic Darter is restricted to the lower Duck River system in west-central Tennessee. They live primarily in pools and riffles with slab-rock and gravel substrate in headwater creeks. Like other members of the subgenus Catonotus, this species spawns on the underside of flat rocks. As the common name suggests, males have round structures on the rays of their second dorsal fin that are hypothesized to serve as an “egg-mimic” to attract females for spawning.