Grunion lay their eggs. The male then wraps himself around the female to deposit his sperm, and for the next 10 days the grunion eggs remain hidden in the sand. At the next set of high tides, the eggs hatch and the young grunion are washed out to sea. A related species, the false grunion ("Colpichthys regis") lives in the Gulf of California. Although the fish looks and acts similarly, it does not have the same breeding method. The currently recognized species in this genus are: Grunion were originally classified as part of the Atherinidae family of silversides, but are now
Grunion regulations, the resource seems to be maintaining itself at a fairly constant level. The coastal Indians in California harvested grunion during spawning runs. Archeologists have found fossil grunion otoliths (tiny, bonelike particles or stony platelike structures in the internal ear of lower vertebrates) at various Indian campsites. Grunion were mentioned by Spanish explorer Juan Rodríguez Cabrillo in his ship's log dated around 1542. Scientists first identified grunion in San Francisco Bay in 1860. Frank Zappa wrote a song named "Grunion Run" (originally released as a single by The Hollywood Persuaders), as has Jonathan Richman ("Grunion Run" on his album "I,