Tiny (3- to 6-ounce) fish found along the Southern California coast, known for their spawning habits. The "running of the grunion" occurs by the light of the full moon as these silvery fish wriggle their way above high tide to spawn in the wet sand. Legally, grunion can only be caught by hand, though many people snare them with nets or scoops. The moderately fat grunion are best broiled, deep-fried or sautéed. See also fish.