National Geographic : 1969 May
If they miss that series also, they will die. Crouching at the edge of the water to get the best possible look at the grunion, I had the seat of my pants doused by incoming waves. So, wet anyway, I waded into the surf to see what was happening there. Grunion darted around everywhere, trac ing paths of cold and ghostly fire. The night was dark, and they would have been com pletely hidden but for the luminescence their movement caused. Wherever the fish twisted and turned, their motion stimulated millions, perhaps billions, of microscopic one-celled organisms-dinoflagellates-momentarily to turn on their tiny flares.* I had come to Cabrillo as a biologist and observer; many had come simply to watch, still others to catch fish. When grunion run in March, June, July, and August, fishermen with a California license and children under 16 may catch them in unlimited numbers-but only, the law specifies, with bare hands (pages 716-17). None may be taken in April and May, the height of the spawning season. When scaled, cleaned, rolled in flour and cracker crumbs, and deep-fried, these little members of the silversides family (Atherinidae) have a delicate, savory flavor. Elusive as Soap Dropped in a Shower During open season the antics of fishermen are as much fun to watch as the grunion. Beached fish are often easy prey, and the egg laying females are especially vulnerable when imbedded in the sand. But sometimes a grasped grunion can squirt out of the hand like soap in a shower bath and can be as hard to retrieve. One of the least effective yet most popular techniques is to stand in the surf and wait until the grunion start sweeping by. The eager fisherman follows at full speed, diving head long for the nearest fish as it hits the shore. He usually ends up sprawled in the wet sand while the fish wiggles out of reach. In the melee many a bare foot is grabbed in error. Those who get close enough might hear the sound the female fish is reported to make while spawning. Bob Sisson, who took the pictures on these pages, confirms that he has heard it: a noise like the squeak of a mouse, but lower in pitch. The name "grunion" is believed to derive from the Spanish word grui~dn, which means "grunter." Despite the frantic grunion gathering on *A dramatic example of such marine bioluminescence was described by staff naturalist Paul A. Zahl in "Sailing a Sea of Fire," NATIONAL GEOGRAPHIC, July 1960. 720 Embryo glistens in a six-day-old egg. Two eyes bulge like tiny black beads. The tail curls around the food supply-the round yolk and adjacent oil bubbles. Flipping to freedom: A grunion fry un coils like a spring as the thin egg case breaks. Eggs mature in about 10 days, hatching when an incoming tide exposes them and agitates the sand. Instant fish. Once free of their egg cases, these quarter-inch fry swim directly into the surf. A fourth embryo still curls inside its egg. The hatchlings will grow to six inches or more as adults.