National Geographic : 1995 Dec
Out of blue gloom, a manta materializes at dawn with a company of fusilier fish parad ing the Goofnuw inlet in the Yap Islands. My diving partner, Bill Acker, and I hold our breath so that exhaust bubbles won't disturb the giant. As the inlet begins to fill with the rush of a rising tide and growing light, three more mantas beat by us on silent wings. These are creatures seen along the edges of reefs, where ebbing tides pump rivers of eggs, larvae, and tiny crus taceans into the open sea. The rays follow the tides, feeding nonstop. Found worldwide across the equatorial belt, mantas are seen regularly by divers in the Yap Islands, off the Kona coast of Hawaii, and at San Bene dicto, one of the Revillagigedo Islands, 250 miles south of Mexico's Baja California. Much about giant mantas their breeding, birthing, and life span-remains poorly understood. Even the number of species is under review. "When in doubt I always use the oldest classification, Manta birostris, which was first described in 1798," says ichthyologist Jack Randall of Hawaii's Bishop Museum. Smaller mantas are classi fied in nine species of the genus Mobula. Off the coast of Australia some swim together, looking like stealth bombers in formation (right). For all their placid ways, giant mantas were a threat in the days when divers wore hel mets with air hoses connected to shipboard pumps. Yashinori Maeda, one of the last hard hat pearl divers in Australia told me this story: "I was collecting oysters 70 feet down when a giant manta snagged my air hose and safety line. Then it must have panicked. It was so strong that it pulled my helmet off the breastplate, breaking the screw threads. "Wearing lead shoes and a lead belt, I could not swim to the surface. I was drowning when my tender saw I was in trouble and pulled me up." Manta!