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
3D Virtual Creature Evolution (from zero, as not having an influence on fitness, to one, or having maximum influence) to determine the fitness goal. What generations the fitness function applies to can also be set. The environment, or “Terrain”, is then determined. This includes a flat plain, bumpy terrain (in which a hill is generated around creature that constantly inclines as distance is traveled from the creature’s spawning point), water (a low gravity simulator, non-functional), and “spheres” (spheres are generated above creature to catch). Everything in the simulation is viewed from a first person viewpoint. After settings are determined, the first generation is generated