Grunion The Gulf grunion, with its smaller eggs, is unique in that it spawn during both night- and daytime. Although some other fish species leave their eggs in locations that dry out (a few, such as plainfin midshipman, may even remain on land with the eggs during low tide) or on plants above the water (splash tetras), jumping onto land "en masse" to spawn is unique to the grunion, capelin and grass puffer. Grunion feeding habits are not well known. They have no teeth and feed on very small organisms such as plankton. In a laboratory setting, grunion eat live brine
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,