Grunion greeters came out in large numbers to observe the mating ritual of the small critters at Doheny State Beach. SCNG FILE PHOTO

California grunion swim to shore to lay their eggs on Cabrillo Beach, San Pedro. Cabrillo Marine Aquarium offers its last Meet the Grunion program each summer.

Sound The gallery will resume in seconds

California grunion, the only known fish whose fertilized eggs incubate out of the water, are shown on Cabrillo beach in San Pedro during a program run by the Cabrillo Marine Aquarium. Grunion time their egg laying three or four days after the highest tide linked to a full or new moon. Their eggs sit below the sand, where they incubate for 10 days, at which point another equally high tide comes in and drag them into the sea. The influx of seawater and the shaking motion causes them to instantly hatch. (AP Photo/Gary Florin, Cabrillo Marine Aquarium)

Thousands of grunion come offshore to lay and fertilize their eggs after a new and full moon at Doheny State Beach from March through August. SCNG FILE PHOTO

Thousands of grunion come ashore to lay and fertilize their eggs at Doheny State Beach. Grunion activity happens from March to August on the second, third and fourth days after a full moon. SCNG FILE PHOTO



A male grunion wraps around a female as she lays thousands of eggs during the highest of tides at Doheny State Beach. Grunion activity happens from March to August on the second, third and fourth days after a full moon. SCNG FILE PHOTO

Beachgoers get up close with grunion. The fish species was studied by an associate professor at California State Long Beach to see how the species could adapt to climate change.

FISH OUT OF WATER: A few grunion were washed ashore to the delight of Sammi Scotto a few years ago at Doheny State Beach. A few dozen people waited desperately to see the grunion running. SCNG FILE PHOTO

They dance in the moonlight, their tiny silver bodies entwined as they flop around, trying to find just the right place on the sand.

As the grunion come out of the ocean water to spawn — the season is kicking off this month — bundled-up beachgoers will flock to the coast in the dark, clutching flashlights, to witness the unique mating ritual and hoping to get a glimpse of the curious creatures.

The Grunion Fish-tival on Friday, March 22, at Cabrillo Marine Aquarium in San Pedro marks their return and celebrates the late-night ritual of grunion gazing.

“Could you imagine fish actually coming out of the water as part of their reproductive cycle? Fish are supposed to be in the water, but these fish come out just to reproduce,” said Jeff Landesman, the aquarium’s head aquarist. “The timing is impeccable. They have to have the timing just right.”

Grunion running, as it is known, only happens on select nights following the full and new moons, making it somewhat predictable. But be warned, sometimes they are no-shows.

Grunion typically live quietly in nearshore waters. But the full and new moons from early spring through summer draw them to swarm onto sandy Southern California beaches, according to the California Department of Fish and Wildlife.

“How did they know all this? We have no idea. How do they know what beach to go on?” Landesman wondered. “Some (beaches) they know are good reproductive areas. This common little fish we can see wiggling around our ankles know so much more than we know. It’s incredible.”

Grunion show up just after the peak of high tide. They swim ashore with the waves, and the females digs holes into the sand to lay their eggs. The male grunion wrap themselves around the female to fertilize the eggs. Then, when the next wave washes ashore, the fish are returned to the sea.

“The whole beach, just covered up to your ankles,” Landesman said. “You can’t even see sand. It’s just wall-to-wall flapping silvery fish. If you’re ankle deep, it’s in front of you, to the left, to the right. The whole beach can be just covered.”

But make sure you don’t spook the scouts. It’s advised to keep flashlights off and to stay quiet when the first few fish show up on the sand. It’s those fish that signal to the rest that it’s safe to come out.

“If they don’t return to the ocean, all those other fish waiting will not come up,” said Landesman, who has been hosting grunion talks for more than 30 years. “Be calm, don’t worry. Turn your lights off. If you’re patient, each wave will bring more and more fish. You just have to be patient.”

A female, which typically lives for about four years, can lay more than 3,000 eggs every two weeks. The eggs remain in the sand for about 10 days, until the tides are once again high enough to wash out the embryos, the waves helping them to hatch.

Regulations require that people only gather grunion with buckets and hands, and only during March, June, July and August — with April and May closed season. Anyone over 16 needs a sport fishing license.

Grunion show up from San Francisco to Baja and are mostly found south of Point Conception. Along Baja and parts of Mexico, they come up to shore during daylight.

They seem to like sandy beaches with a gradual slope. Among their favorite spots are Doheny State Beach, Huntington Beach, Crystal Cove, San Pedro, and areas of San Diego.

“Nowhere else in the world can you see a fish come up on the beach,” Landesman said. “If you go somewhere else and tell people it happens, they won’t even believe it.”

Once they catch grunion, some people like to fry them, others gut and sauté them — though reviews are mixed on whether they are tasty.

If you go

What: The Grunion Fish-tival runs from 8 p.m. to midnight Friday, March 22. Guests are encouraged to wear grunion-theme aluminum hats to greet the grunion. The best grunion-themed foil hats will win prizes.

Fish-tival goers will be able to hatch grunion eggs, participate in grunion arts and crafts, watch a classic grunion video and touch live tidepool animals. Attendees 16 or older must have a valid 2019 California fishing license to catch grunion during open months.

Cabrillo Marine Aquarium is hosting Meet the Grunion events through spring and summer, teaching about mating rituals and growth of the fish.

On grunion nights the aquarium opens at 8 p.m.; an auditorium program will begin at 9 p.m. followed by guided grunion observation at the beach. Bring warm clothing, a chair and a flashlight.

Where: 3720 Stephen M. White Drive, San Pedro.

Tickets: $5 adults; $1 seniors, students and children.

Information: cabrillomarineaquarium.org or 310-548-7562.

Schedule: The California Department of Fish and Wildlife predicts grunion runs at Cabrillo Beach near the Los Angeles Harbor entrance. Timing varies at different places along the coast. San Diego runs are about five minutes earlier and Santa Barbara about 25 minutes later than the following times. There’s no take allowed during April and May; observation only.

March:

21: 10:45 p.m.-12:45 a.m.

22: 11:20 p.m.-1:20 a.m.

23: Midnight-2 a.m.

24: 12:40-2:40 a.m.

April: (observation only)

5: 10:20 p.m.-12:20 a.m.

6: 10:40 p.m.-12:40 a.m.

7: 11:10 p.m.-1:10 a.m.

8: 11:40 p.m.-1:40 a.m.

19: 10:10 p.m.-12:10 a.m.

20: 10:40 p.m.-12:40 a.m.

21: 11:15 p.m.-1:15 a.m.

22: 11:50 p.m.-1:50 a.m.

May: (observation only)

4: 9:40-11:40 p.m.

5: 10:10 p.m.-12:10 a.m.

6: 10:40 p.m.-12:40 a.m.

7: 11:15 p.m.-1:15 a.m.

18: 9:35-11:35 p.m.

19: 10:10 p.m.-12:10 a.m.

20: 10:45 p.m.-12:45 a.m.

21: 11:20 p.m.-1:20 a.m.

June:

3: 9:45-11:45 p.m.

4: 10:20 p.m.-12:20 a.m.

5: 11:05 p.m.-1:05 a.m.

6: 11:55 p.m.-1:55 a.m.

17: 9:50 -11:50 p.m.

18: 10:20 p.m.-12:20 a.m.

19: 11 p.m.-1 a.m.

20: 11:35 p.m.-1:35 a.m.

July:

2: 9:30-11:30 p.m.

3: 10:15 p.m.-12:15 a.m.

4: 11 p.m.-1 a.m.

5: 11:50 p.m.-1:50 a.m.

16: 9:35 -11:35 p.m.

17: 10:10 p.m.-12:10 a.m.

18: 10:40 p.m -12:40 a.m.

19: 11:15 p.m.-1:15 a.m.

August:

1: 10:05-12:05 a.m.

2: 10:50 p.m.-12:50 a.m.

3: 11:45 p.m.- :45 a.m.

4: 12:40-2:40 a.m.

15: 9:55-11:55 p.m.

16: 10:25 p.m.-12:25 a.m.

17: 10:55 p.m.-12:55 a.m.

30: 9:55-11:55 p.m.

31: 10:45 p.m.-12:45 a.m.

September: