Dancing in the Dark

Though a lot of fish swim in our sea, we have one very local species found only along the southern California coast: the grunion. Often thought, as is the green flash, to be a myth, both the green flash and the grunion (Leuresthes tenuis) are very real and so are grunion runs.


The runs happen by the light of the silvery full or new moon, at the peak of the high tide toward the middle of the night. California’s resident grunions, alerted, possibly, by the change in pressure of rising tide following the full and new moons, swim to shore on incoming waves to dance their special mating dance. It is quite a sight.The females “stand” up right on their tails and all 5-6” of them twirl their way down into the wet sand to lay their eggs. The males then wrap around her and fertilize the eggs. Off they go jumping onto the next wave back into the ocean where they live their fairly ordinary lives in nearshore waters. Wave after wave can bring in hundreds even thousands of grunions. Really.


However, because schedules of grunion runs, as their moon-linked mystical appearance is termed, is only approximate, there is no guarantee they will show up. But, there are several runs each year, March through August. So, if at first you don’t succeed, try and try again—and take your flashlight. Female grunions are capable of repeating this ritual four to eight times per year laying some 3,000 eggs in the biweekly seasons. Counting up, each fish may produce many thousands of eggs during her four year life.


Whether or not you witness this event, those buried eggs incubate till the high tides return to carry out the developed embryos when they are about 10 days old. Stimulated by the action of the waves they hatch as into the ocean they go and grow up.


There are regulations on grunion runs. There are specific “no take” seasons and other times when you can catch them using only your hands. Nets, equipment, dug out holes and/or pits are prohibited, and a California sport fishing license is required for those 16 years old and up. To find the grunion run schedules: californiabeaches.com