The California Grunion

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Grunion man, grunion man,
Running for grunion as fast as he can,
When he finds them he puts them in a can,
Grunion man, grunion man.

Grunion man, grunion man,
Squirming and twisting as fast as he can,
When he's finished, he does it again,
Grunion man, grunion man.

Grunion man, grunion man,
Nobody knows how he can,
Find those grunion all over the land,
Grunion man, grunion man.

Silly poem composed by Homey G for Sporty

The California grunion are one of the most amazing creatures on Earth. Unlike most fish, they lay their eggs on land. No other marine fish goes to such lengths.

Grunion runs in California are legendary. Between March and August, during the spring tides, 2-3 days after the new and full moons, the grunions come ashore in the thousands to lay their eggs. They time their arrival right after the peak of the high high tide. That way, they insure that their eggs will have sufficient time to develop before the next spring tides arrive some 10-14 days later.

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Grunion runs occur something like this. On the days mentioned above, large schools of male and female grunions gather in the shallow waters of the surf zone. At about the time of the high high tide, a few male scouts run up with the wave and appear to check things out. If there are lots of lights or people or a flock of hungry seagulls standing by, then they move further down the beach. When the scouts decide that the coast is clear, a wave of grunion rushes up on the shore, and the sexual frenzy commences.

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First, the females dig their tails and bodies into the wet sand. At about the depth of 2/3 of their body length, they deposit their eggs, anywhere from 100 to 3000, according to the reports that I have read. The males, who outnumber the females, immediately wrap their bodies around the submerged female and spray her with sperm. There is no act of copulation among grunion. The milt (as fish sperm is called) runs down the body of the female and fertilizes the eggs. Because the water from the wave on which the grunion arrived sinks into the sand, the milt is carried with it, helping it to reach the eggs.

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One to several males may court on a female; males continue to produce milt and fertilize eggs throughout the evening. Females lay eggs once a season, as far as I know. Once the males are finished, they run off in search of another female. The females are left to fend for themselves, wriggling and struggling out of the sand, then flopping back towards the waves and into the night.

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Grunion appear to be limited in range from about Morro Bay to halfway down the Baja peninsula. In Baja, grunion runs occur during the day because the high high tides are earlier there. Grunion runs here in southern California always occur at night.

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Once the eggs are deposited, they develop very quickly. Within ten days, a 1 mm nearly fully developed larval fish is formed. When the water and waves disturb the eggs 10-14 days later, the eggs immediately burst open and the grunion swim out to sea. What happens to them after that, nobody really knows.

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How the grunion know when to arrive on the beach, how they know which beach is the best and where they go when they are not flopping around on the beach is one of the great mysteries of the sea. Nonetheless, they appear to exert a powerful and magic effect on the human psyche. More than one student has related to me their success in love following a grunion run. While I can't speak about that personally, I can say that experiencing a grunion run is a treat. They demonstrate to us the power of the sea and the beauty of its inhabitants.

Come join us on our next grunion run. You won't regret it.