Rainbow Darter (Etheostoma caeruleum)

Description: 

The Rainbow Darter is widespread in eastern North America in the Great Lakes and Mississippi River drainages. They are found in rocky riffles and runs in small creeks to medium rivers. As the common name suggests, Rainbow Darters have a wide array of colors on the body and fins of breeding males. They are frequently the dominant darter in smaller streams where they occur.