Fish living in Coral Reefs Small fish inhabit the many holes and crevices on this portion of the reef, and many larger fish including sharks, jacks, barracudas and tunas patrol the buttresses and grooves in search of food (Barnes, R.D., 1987; Lalli and Parsons, 1995; Sumich, 1996). http://coris.noaa.gov/about/what_are/ Coral reefs are some of the most diverse and valuable ecosystems on Earth. Coral reefs support more species per unit area than any other marine environment, including about 4,000 species of fish, 800 species of hard corals and hundreds of other species. Scientists estimate that there may be another 1 to 8 million undiscovered species of organisms living in and around reefs (ReakaKudla, 1997). This biodiversity is considered key to finding new medicines for the 21st century. Many drugs are now being developed from coral reef animals and plants as possible cures for cancer, arthritis, human bacterial infections, viruses, and other diseases. http://oceanservice.noaa.gov/education/kits/corals/coral07_importance.html
ecology The Great Barrier Reef supports a diversity of life, including many vulnerable or endangered species, some of which may be endemic to the reef system.[30][31]
Green sea turtle on the Great Barrier Reef
Thirty species of whales, dolphins, and porpoises have been recorded in the Great Barrier Reef, including the dwarf minke whale, Indo-Pacific humpback dolphin, and the humpback whale. Large populations of dugongs live there.[32][33][31] Six species of sea turtles come to the reef to breed – the green sea turtle, leatherback sea turtle, hawksbill turtle, loggerhead sea turtle, flatback turtle, and the olive ridley. The green sea turtles on the Great Barrier Reef have two genetically distinct populations, one in the northern part of the reef and the other in the southern part.[34] Fifteen species of seagrass in beds attract the dugongs and turtles,[32] and provide a habitat for fish.[35] The most common genera of seagrasses are Halophila and Halodule.[36]
Saltwater crocodiles live in mangrove and salt marshes on the coast near the reef.[37] Nesting has not been reported, and the salt water crocodile population in the GBRWHA is wide-ranging and with a low population density.[38] Around 125 species of shark, stingray, skates or chimera live on the reef.[39][40] Close to 5,000 species of mollusc have been recorded on the reef, including the giant clam and various nudibranchs and cone snails.[32] Forty-nine species of pipefish and nine species of seahorse have been recorded.[38] At least seven species of frog can be found on the islands.[41] 215 species of birds (including 22 species of seabirds and 32 species of shorebirds) are attracted to the reef or nest or roost on the islands,[42] including the white-bellied sea eagle and roseate tern.[32] Most nesting sites are on islands in the northern and southern regions of the Great Barrier Reef, with 1.4-1.7 million birds using the sites to breed.[43][44] The islands of the Great Barrier Reef also support 2,195 known plant species; three of these are endemic. The northern islands have 300-350 plant species which tend to be woody, whereas the southern islands have 200 which tend to be herbaceous; the Whitsunday region is the most diverse, supporting 1,141 species. The plant species are spread by birds.[41] Seventeen species of sea snake live on the Great Barrier Reef. They take three or four years to reach sexual maturity and are long-lived but with low fertility. They are usually benthic, but the species that live on the soft sediment differ from those that live on the reefs themselves. They live in warm waters up to 50 metres (164 ft) deep and are more common in the southern than in the northern part of the reef. None of the sea snakes found in the Great Barrier Reef World Heritage Area are endemic to the reef, nor are any of them endangered.[38] More than 1,500 species of fish live on the reef, including the clownfish, red bass, red-throat emperor, and several species of snapper and coral trout.[32] Forty-nine species are known to mass spawn, with eighty-four other species found on the reef spawning elsewhere in their range.[45] There are at least 330 species of ascidians found on the reef system,
ranging in size from 1 mm-10 cm (0.04–4 in) in diameter. Between 300-500 species of bryozoans are found on the reef system.[40] Four hundred species of corals, both hard corals and soft corals are found on the reef.[32] The majority of these spawn gametes, breeding in mass spawning events that are controlled by the rising sea temperatures of spring and summer, the lunar cycle, and the diurnal cycle. Reefs in the inner Great Barrier Reef spawn during the week after the full moon in October, but the outer reefs spawn in November and December.[46] The common soft corals on the Great Barrier Reef belong to 36 genera.[47] Five hundred species of marine algae or seaweed live on the reef,[32] including thirteen species of the genus Halimeda, which deposit calcareous mounds up to 100 metres (110 yd) wide, creating mini-ecosystems on their surface which have been compared to rainforest cover.[48] http://en.wikipedia.org/wiki/Great_Barrier_Reef#Environmental_threats
There are also many species of fish that live in the Great Barrier Reef (over 140 species). Some of them are very large while others are very small. Some of the larger animals are the Great White Shark-a large (normally 600 IBS!) that is featured in a movie called Jaws, another is the hammerhead- a large ,wide headed predator. some of the smaller ones are the White Sea Urchin, Basket Fish, Four Eyed Butter Fish, and the Soldier Fish. To learn more about sea life, go to Coral Renters, a page about sea creatures that live in reefs throughout the world http://library.thinkquest.org/6416/great.htm Many fish travel in packs to protect themselves from the many predators hiding in the coral caves. A few of these ever present predators are the infamous eels, Great White sharks, and including several types of sharks. These sharks have a hunger for the many small & large fish in the surrounding areas. These sharks include the Gray Tipped shark, and the
many Blue sharks. The camouflage that the fish have adapted to using in coral reefs protect them from the deadly sharks. One type of fish the Scorpion Fish uses camoflauge for protection. A few fish such as the "Milk Fish" as the name was dubbed to it, for when the fish is squeezed or bitten it lets a milky substance from its skin that is annoying and distasteful to predators. Though the coral reef has many fish that are well defended and hidden predators still find food in the reefs. Several small types of fish who rely on speed for protection, soon learn that eels have also evolved to be quicker and more efficient hunters. Fish tend to live in crevices and only come out in groups or "schools" of fish because the more eyes the more likely a predator will be spotted and avoided than if 3 fish were in a group instead of 50 or 60. Several animals that are not fish such as lobster and crabs live in coral reefs. The Flamingo Tongue Snail, the Red Coral shrimp,the Ghost Crabs, the Sand Shrimp and the Moon Snails all live in the coral. These animals also have bright colors like the other fish. A few other creatures that arent fish that live in the coral reefs are the White Sea Urchin , the Basket Starfish, and the Rock Crab all live in the coral reefs. Jellysifh also live in certain areas of coral reefs. http://library.thinkquest.org/6416/coral_renters.htm