It hosts 5,000 types of mollusks, 1,800 species of fish ... Time and tides and a planet in eternal flux brought the Great Barrier Reef into being millions of years ago, wore it down, and grew ...

The Great Barrier Reef is the world's largest and most diverse reef ecosystem and is home to 400 types of coral, 1,500 species of fish, and 4,000 types of mollusks, according to UNESCO.

An aerial view of Vlassof Cay in the Great Barrier Reef, Nov. 14, 2012 in Cairns, Australia. Credit: Mark Kolbe/Getty Images The bad news: 22 percent of Australia's Great Barrier Reef has died.

Coral reefs provide an important ecosystem for marine life, offering food and shelter among their crevices and branches for animals including fishes, molluscs ... biggest and best-known are the reef ...

During high school I had the opportunity to travel to Australia and dive on the Great Barrier Reef ... and can occur in symbiosis with mollusks, sponges, flatworms, protists, some ciliates, and ...