Headwater darter
Etheostoma lawrencei
The headwater darter is a species of darter endemic to the eastern United States where it is found in Kentucky and Tennessee in the upper Green River system down to the Mud River, in the Cumberland River and upper Salt River systems. It is an inhabitant of streams up to about 5 metres wide with gravel or cobble substrates. Males of this species can reach a length of 6.2 centimetres SL while females only reach 5.7 centimetres .