The Great Barrier Reef, just off the continent of Australia, has one of the largest amounts of animal diversity in any marine habitat. Living among the coral is nearly 1,500 species of fish, 4,000 kinds of mollusks, and more than 400 species of sponges. In addition there are also many types of starfish, crab and shrimp that also call the reef home. Many animals also migrate into the reef to use the area as a breeding ground. These animals include the Humpback whale, sea turtles and Dugongs.
The corals that make up the Great Barrier Reef are actually animals, although they may not seem like it. The reef itself boasts several hundred different species of coral that come in many different colors and shapes. Coral Reefs are home to more than a quarter of all marine fish species, despite making up a meager one percent of the oceans environment. As the Earth's temperatures continue to warm coral reefs are dying off at an alarming rate.
The species of fish that inhabit the coral reefs are so numerous it makes it impossible to list them. Some of the notable species of fish include the red bass, which can live to an age of 50 years, and the coral trout which changes gender as they grow, beginning life as female and later switching to males as they grow. Other species of fish include angelfishes, gobies, mandarin fishes, and manta rays.
Sea Turtles also live among the coral during portions of their lives. Among the turtles that come to the reef is the Green Sea Turtle. This type of turtle is endangered due to being hunted for their shells, eggs and meat as well as suffering from boating accidents and the destruction of their habitats. Turtles come to the Great Barrier Reef each year to lay their eggs in the sand. The temperature of the sand decides what gender the baby turtles will be. The turtles that survive will return to the same spot to breed when they are mature.
Dugongs, close relatives of the manatee, also live among the coral. These large animals live in large herds and spend their time grazing on sea grass. These animals can live an astounding 70 years. However they produce young only every 3 to 7 years and so can go down in numbers very quickly if their populations are not carefully monitored. These animals also suffer from accidents with boats and have frequent run-ins with nets that do not end well. They also suffer from the destruction of their habitat and the pollution that floods the ocean each year.
Among the many animals that call the reef home there are several that have proven to be very dangerous to humans. There are two types of jellyfish, The Irukandji and the box jellyfish, which are potentially fatal to humans. Both of these are found in specific areas and divers and snorkelers should be aware of safe areas before venturing out. Another creature with the potential to kill a human is the blue ringed octopus. This small cute creature is about the size of a golf ball but has poison so powerful it could kill a human in just a few minutes and there is no known antidote.