Tis the season for the . The silvery fish were set to make their first appearance of the year Thursday night, according to the California Department of Fish and Game.
From now until about August, the grunion will wriggle ashore to spawn. This ritual takes place the night of full or new moons, and continues for about three nights following, according to the state department.
"This doesn’t happen anywhere else in the world, and it’s a very unique experience," Melissa Studer, project director for Grunion.org, a Pepperdine University group of scientists, environmentalists and community members, .
During a grunion run, the fish leave the ocean to spawn on beaches. The females create nests in the sand, where they deposit eggs. The males follow, curving around the females to fertilize the eggs.
Females lay between 1,600 and 3,600 eggs during one spawn, according to the state department. The eggs hatch about 10 days later when there is another high tide.
Grunion, a toothless fish, typically grow to be between five and six inches long. While humans, other large fish and shark eat grunion; shorebirds prey on grunion eggs.
"Look for the shorebirds—they always know where to find the grunion," Studer said.
Grunion runs can be seen by beachgoers at Cabrillo Beach in San Pedro, according to the state department. Another main landing spot for the grunion has been in Hermosa Beach, near 33rd Street.
Some other beaches known to have runs are Malibu, Santa Monica, Venice, Cabrillo Beach, Long Beach, Belmont Shore, Seal Beach, Huntington Beach, Newport Beach, Corona del Mar, Doheny Beach, Del Mar, La Jolla, Mission Beach and the Coronado Strand.
See accompanying fact sheet under photo for a full schedule of expected grunion runs this season.