The first grunion run of the year is expected near Rancho Palos Verdes, California. The fish, which measure six to eight inches in length, are found only in Southern California and northern Baja California. They typically run for two hours each night from Wednesday through Saturday. The female grunion can lay around 3,000 eggs at once during a mating season, and the male grunion then rides the tide to the eggs and fertilizes them before returning to the ocean.