How do California grunion spawn on beaches?

The California grunion (Leuresthes tenuis) exhibits a unique reproductive behavior by spawning directly on the beach rather than in the water. During the warm months, these fish school in the surf at the peak of a full or new moon, known as a spring tide.12

Once the tide reaches its highest point, the fish move onto the shore. The female then buries her eggs in the sand. These eggs remain in the sand for approximately two weeks, protected from the ocean until the next spring tide occurs. When the subsequent high tide inundates the area, the eggs hatch and the young are carried out into the ocean.12