A detailed study of the annual march of 50 million crabs on Christmas Island to spawn. This triggers the arrival of whale sharks and other marine creatures at Christmas Island to feed on the... Read allA detailed study of the annual march of 50 million crabs on Christmas Island to spawn. This triggers the arrival of whale sharks and other marine creatures at Christmas Island to feed on the mass spawn.A detailed study of the annual march of 50 million crabs on Christmas Island to spawn. This triggers the arrival of whale sharks and other marine creatures at Christmas Island to feed on the mass spawn.