If you were walking along a California beach and saw a group of fish dancing on their tails in the sand, you might think your eyes were playing tricks on you. But a small, sardine-like fish called the grunion performs just such a dance on the beach every year!
In spring and summer, schools of grunions gather off the coast of California. When the fish are carried by waves onto the shore, the female grunions stand up on their tails and spin around in a dance.
In so doing, they dig holes in the sand, holes in which they then lay their eggs. The male grunions take over the dance in the holes and fertilize the eggs.
This performance ends when the next wave breaks on shore and carries the males and females back into the ocean.
Later, when the eggs hatch, the baby grunions dance their way back across the sand to the ocean. A year later, these babies, now full-grown adult grunions, will return to the beaches for a repeat performance of their strange beach dance!