Regulation and Significance of Color Patterns of the Spotted Kelpfish, Gibbonsia elegans Cooper, 1864 (Blennioidei: Clinidae)

The spotted kelpfish, Gibbonsia elegans Cooper is common in shallow waters off southern California, living in close association with either red or brown algae or green surfgrass. Kelpfish generally match the color of their plant habitats and occur in red, green, or brown color morphs. They are not sexually dimorphic in color morph, but exhibit sexual differences in belly color and body size. Almost all Gibbonsia match the color of their plant habitat. Their diet primarily consists of epiphytic crustaceans, which in turn, match the colors of the plants. The roles of epiphytic invertebrates and plant backgrounds in regulating color morphic changes were tested in laboratory experiments. Results indicated that Gibbonsia morphs are capable of slow color changes (within several weeks), which are apparently not regulated by diet and governed by plant background color alone. In situ color changes were more pronounced and occurred more rapidly than those in the laboratory experiments. Gut contents and laboratory behavioral experiments showed that Gibbonsia more frequently captured crustaceans which did not match the plant backgrounds.