National Geographic : 1991 Jan
SILVERY NEBULA of bull's eye fish swirls about near Monkey Rock off Dirk HartogIsland in a cavern lit by hand-held lights. "The fish spend the day inside the cave hiding out from predators, then explode out of the cave at night like bats to feed," says photographer David Doubilet. He had his own quick trip out of the cave when a sudden tidal surge carriedhim, helpless, 50 feet to the surface. Then another surge carried him back down, depositing him exactly where he had begun. Inside the cave an orange-spotted grouper strikes a defensive pose, exposing the opening to its esophagus and rows of gill rakers, used to direct food away from the gills. Cleaner shrimp and tiny fish called wrasses watch for such a yawn as a signal to enter and pick parasitesfrom inside the carnivore'smouth.