Teardrop darter

The teardrop darter (Etheostoma barbouri) is a species of darter endemic to the eastern United States. It is only found in Kentucky and Tennessee, where it occurs in the middle to upper reaches of the Green River drainage. It inhabits small rivers and creeks and rocky pools where it feeds on the larvae of blackflies and midges, immature stages of caddisflies and mayflies, and cladocerans and copepods. This species can reach a length of 6 cm (2.4 in), though most only reach about 4.2 cm (1.7 in).