California Grunion
Leuresthes tenuis

Physical Description

    • Small, slender fish
    • Pearlescent blue-green backs and silver sides and bellies
    • Forked tail
    • Large black eyes and no teeth

Range

    • The coasts of California, and Baja California, Mexico

Habitat

    • Inhabit nearshore waters, from surf zone to a depth of 60 feet

Diet

    • Small zooplankton
    • Not filter-feeders; use large eyes to hunt individual plankton prey rather than filter large amounts of water

Predators

    • Halibut, corbina, guitarfish, seals, sea lions, sharks, dolphins, and squid feed on grunion in the water
    • Herons, egrets, and other seabirds eat spawning grunion while they are on shore

Interesting Facts

    • Grunion are perhaps most famous for their Grunion Runs, their spawning events every spring and summer. From March to September, but especially March to early June, hundreds of grunion ride waves out of the water and gather on the beach to spawn in the sand. This happens for the four days after each full moon and new moon. The grunion leave the water right after high tide and stay out of the water for several hours.
    • After the Grunion Run, the eggs are left buried in the sand, out of the water, for approximately two weeks. At the next very high tide of a new moon or full moon, the larvae hatch and re-enter the ocean.
    • During some months of the Grunion Runs, grunion can be recreationally fished, but only by hand! No gear allowed.

Sources: CaliforniaBeaches.com; Oceana; Grunion.org; California Dept. of Fish and Wildlife

Photo: Matthew Meier 

Want to watch the grunion run in person? Find the best Grunion Run beaches and dates near you: https://www.californiabeaches.com/grunion-run-schedule/

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