Darter
Darter, the name of a group of small fish of the perch family. Darters swim about in short dashes, propelled by fins on the breast. These fish have no commercial value but are a popular attraction in aquariums. They have brilliant markings, especially in metallic green and bright red.
Darters do not have gas bladders. Some burrow in the sand, leaving only their eyes showing. The female of one species, the Johnny darter, lays eggs under stones, and the male guards them. The logperch of the Great Lakes region and the Mississippi Valley is the largest darter, measuring up to eight inches (20 cm) in length. The snail darter was once considered so endangered that in 1980 construction of the Tellico Dam on the Tennessee River was almost halted because it would have destroyed this darter's only known habitat. However, after the dam was built, the species was discovered in a few other Tennessee rivers and is no longer considered endangered.
Darters belong to the family Percidae. The Johnny darter is Etheostoma nigrum; the logperch, Percina caprodes; the snail darter, P. tanasi.