Greenside Darter (Etheostoma blennioides)

Description: 

The Greenside Darter is a wide-ranging species found in the Great Lakes and Mississippi River drainages, including the Tennessee and Cumberland river drainages, in eastern North America. It is found in a wide range of habitats, predominately riffles in creeks to medium rivers. Greenside Darters have a coloration of W’s and X’s on their lower side, which turn green in breeding males. They also have large pectoral fins and can reach a maximum size of 6.75 inches, which is the largest species in this genus!