The kelp greenling is a fish with great differences in color between males and females. The female has striking yellow fins with a light-colored body and reddish-brown spots. The male has dark fins and a body that is a grayish-brown with light blue spots concentrated on his front half. The difference between males and females in color and appearance is so pronounced that they were once mistaken for different species.
These fish eat a variety of marine invertebrates as well as smaller fish. Young kelp greenling can be an important food source for salmon and trout.