Marine Wildlife Encyclopedia
Capelin Mallotus villosus
The capelin is a small, silvery relative of salmon that forms large shoals in cold and Arctic waters and is a vital food source for sea birds and marine mammals. The breeding success of some seabird colonies has been linked to the abundance of capelin, and this in turn depends on environmental factors and exploitation by fishing. It is a major food source for Inuit peoples. Capelin are slim fish, with an olive-green back fading into silvery white on the sides. Shoals of this fish swim along with their mouths open, straining out plankton, which is caught on their modified gills. While this is their main source of food, they also eat worms and small fish. In spring, the schools move inshore, the males arriving first and waiting for the females. The male capelin develop a band of modified scales along their sides and use these to massage the female, stimulating her to lay her eggs in the sand.
Capelin and Tidal Breeding
Capelin eggs make a good meal for many invertebrates and fish. To protect their eggs, large numbers of adult capelin swim into very shallow water at high tide and spawn on sandy beaches just below the tideline. Each female produces about 60,000 reddish, sticky eggs, which lie in the sand. When the eggs hatch after about 15 days, the capelin larvae are washed out of the sand by the incoming tide and then swept out to sea on the outgoing tide.