Grunion classified in the family Atherinopsidae along with other New World silversides including the jacksmelt and topsmelt. The California grunion, "L. tenuis", is found along the Pacific Coast from Point Conception, California, to Punta Abreojos, Baja California Sur. They are rarely found between San Francisco in the north and San Juanico Bay, Baja California Sur, in the south. The Gulf grunion, "L. sardina", is found along the coast of Baja California in the Gulf of California. Inhabiting the nearshore waters from the surf to a depth of , marking experiments indicate they are not migratory. They are small, slender fish with
USS Grunion Maru". Her first torpedo ran low, but despite its magnetic pistol it failed to detonate. Two more bounced harmlessly off the "Kano Maru" without exploding. However, the remaining torpedo missed its target and circled back, striking the periscope supports on the submerged submarine without exploding. The damage the torpedo inflicted, combined with a jammed rear dive plane, triggered a sequence of events that caused the loss of depth control. The "Grunion" lunged below her maximum operational depth, and at about 1000 feet would have imploded. What remained of the ship struck the seabed, breaking off about 50 feet of her