Eye dorsally in position extending above profile contour. Jaws oblique, extending back reaching almost to vertical of posterior edge of eye. Upper jaw with a single row of caniniform, curved teeth which are exposed when mouth closed. In lower jaw two rows of smaller caniniform teeth. A distinct cirrus-like flap on the upper edge of eye.
Scales are cycloid and weakly ctenoid.
A series of 4-5 dark blotches on the sides and a black spot on caudal fin base. The flap on the upper edge of eye is bright orange. Spawning season in the summer and fall. This species experienced a population explosion almost immediately after invasion.