Here’s how it works: the female grunion are the first to get in the surf and reach the highest point possible on the beach, or even a bit higher; she pushes her tail into the sand and the male follows her, wrapping his body around hers so that he can fertilize her eggs with milt. The male is quick — 30 seconds or so and he’s on the next wave back to the ocean. It takes the female longer to dig herself out of the sand, but she catches the first wave she can back to the safety of the water.