Leuresthes tenuis
Small silvery fish logged along California's coast, comfortable in 15 to 23°C water and seen year-round on local dives.
A slim, silvery fish around 13 cm long with a fine dark stripe running down its flank and a slightly upturned mouth. Look for tight, fast-moving schools holding just off sandy bottoms rather than reef structure, flashing bright silver as they turn. There's no strong colour contrast or bold pattern to key on, so body shape and that schooling behaviour over sand are your best clues.
Divers usually encounter loose to tight schools hovering or moving over sandy patches close to shore, staying well off any reef or rock structure. They're flighty and keep their distance, scattering as a diver approaches rather than holding position for a close look. Most logs describe brief encounters rather than prolonged observation, consistent with a species that doesn't linger around structure.
This species is famous for its beach-spawning runs, where adults strand themselves on sand at night during high spring tides to lay and fertilise eggs directly in the wet sand, a spectacle watched from shore rather than underwater.
Sightings don't show a clear seasonal pattern, so treat this as a year-round possibility on California dives. Its comfort range of 15 to 23.2°C covers most of the local diving season, from cooler winter water to warmer summer conditions.
Reef neighbours a diver could mistake it for. Use the identification notes above to tell them apart.
Every logged sighting so far comes from California, USA, making it the only real place divers are reporting this species. Within the state it turns up at a handful of sites, typically as an uncommon find rather than a guaranteed one.
Mapping where California Grunion is logged…
All current diver sightings come from California, USA, where it's logged at a small number of coastal sites, usually as an uncommon find.
There isn't a detected seasonal pattern, so it's best treated as a year-round possibility in California waters between about 15 and 23°C.
Look for slender, silvery fish about 13 cm long with a faint dark side stripe, moving in fast, tight schools over sandy seabeds rather than reef.
They typically reach around 13 cm in length, making them a small, easily overlooked schooling fish on a dive.
It's best known for coming fully out of the water onto California beaches during spring high tides to spawn in the sand, a behaviour rarely seen in fish.
Site and sighting data is aggregated from diver logs, iNaturalist and GBIF. For taxonomy and conservation status:
Sun Perch
2,182 sites
