World's Biggest Fish Is A Delicate Feeder

The whale shark -- a massive, polka-dotted creature stretching about 23 feet long -- slowly swam up alongside the scientists' boat. As it neared, they tossed a handful of pre-soaked rice in front of its enormous mouth. The rice rushed in along with the seawater, and the whale shark made a shuddering motion. Until recently, it was difficult to study their filter feeding in detail, since whale sharks can be elusive. Then researchers discovered that hundreds of the animals come to Isla Holbox each summer to feast on plankton carried to the surface by an upwelling of water between the Gulf of Mexico and the Caribbean. Scientists began making annual pilgrimages to this former pirates' lair about 90 miles northwest of Cancun, where the fish are called domino sharks because of their spots...