Grunion The normal lifespan of the grunion is three to four years, although individuals up to five years old have been found. Their growth rate slows after the first spawning and stops completely during the spawning season. Consequently, adult fish grow only during the fall and winter. This growth rate variation causes annuli to form on the scales, which have been used for determining ages. California grunion spawn on beaches from two to six nights after the full and new moon beginning soon after high tide and continuing for several hours. As a wave breaks on the beach, the grunion swim
USS Grunion the exact location indicated by the commander of the "Kano Maru". The sunken object had many characteristics typical of a submarine. In 2007, using a ROV, DSSI/Oceaneering returned to the site and took video recordings of the imploded remains of a submarine, which had markings in English, and propeller guards and limber holes identical to those of the "Grunion". The following year, the US Navy confirmed that the find was the "Grunion". Although it is not absolutely certain, the evidence strongly suggests that the "Grunion" was lost as a result of multiple torpedo failures during her encounter with the "Kano