The rainbow darter (Etheostoma caeruleum) is a native North American fish found in small, fast-moving streams and small to medium-sized rivers. It grows to 2 to 3 in (51 to 76 mm) in length. The species is very sensitive to pollution and silt, staying in clean, pollution-free water. The rainbow darter is easily identified by three dark spots on the back, and blue and orange in the dorsal and anal fins. It is a small perch-like fish found...