Facts: The Rock Greenling

The rock greenling is a bottom-dwelling marine fish that is widely distributed across the North Pacific, occurring from areas near Japan and Russia, across to Alaska, and down to central California. Rock greenlings live in both deep and shallow water. They can be found most commonly from tide pools in the intertidal zone to depths of about 160 feet. However, they can be found as deep as 2,200 feet. They exhibit seasonal vertical migration. They are usually associated with strong currents, exposed rocky reefs, and dense algae. They use the vegetation and kelp in their habitat for shelter and egg laying, avoiding completely open areas. Their distribution is patchy. They feed mainly at night on the seafloor. Rock greenlings feed on a wide variety of food, such as algae, invertebrates like cephalopods and crustaceans, fish eggs, and small fish. Their body varies in color, with males being brighter, but they are usually greenish to brown with darker modeling. Their fins have dark bars or blotches. Five lateral lines run along their body. The inside of their mouth is bluish. A single pair of cirri is above the eyes. Most males tend to have red blotches on their sides. Females are generally larger than males. They can grow up to 24 inches in length. They are thought to live up to 18 years, and they mature at 3 or 4 years old. Spawning typically takes place between June and September, When seaweed growth starts to accelerate in the spring, the males take on an iridescent turquoise color along their back, while the spawning females are primarily dark green. Each female will lay 14,000 to 103,000 eggs on seaweed, vegetation, or in rock crevices. Eggs are guarded by the males. The showy colors of the nest-guarding males disrupts their visibility among the bright green, gold, and red seaweeds. Rock greenlings are occasionally targeted by recreational fishers. They are sometimes displayed in public aquariums. For more marine facts, click the SUBSCRIBE button!!