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
USS Grunion she patrolled north of Kiska Island, stated she had been attacked by a Japanese destroyer and had fired torpedoes at her with inconclusive results. She operated off Kiska throughout July and sank two enemy patrol boats as she waited for enemy shipping. On 30 July, the submarine reported intensive antisubmarine activity and was ordered back to Dutch Harbor. The "Grunion" was never heard from again. Air searches off Kiska were fruitless, and on 5 October the "Grunion" was reported overdue from patrol and assumed lost with all hands. Her name was stricken from the Naval Vessel Register on 2 November