[DOC] [TLE] Corals, Coral Pictures, Coral Facts - National Geographic [PAR] Corals are so sensitive to climatic change that scientists study coral reef fossils to 
... Coral organisms, called polyps, can live on their own, but are primarily ... As 
colonies grow over hundreds and thousands of years, they join with other ... Giant 
Clam ... Find out the sizes that these sea creatures are capable of attaining. [DOC] [TLE] About Coral Reefs - Coral Reef Adventure [PAR] Millions of corals have built colonies in this way over thousands of years to ... In 
the Coral Reef Adventure film, viewers can see a broad diversity of tropical .... 
Corals are tiny animals, called polyps, that are related to and look like sea 
anemones. ... corals and giant clams, also have symbiotic relationships with 
these algae. [DOC] [TLE] Corals and Coral Reefs | Smithsonian Ocean Portal [PAR] Coral reefs are the most diverse of all marine ecosystems. ... substrate and 
become polyps after a few days or weeks, although some can settle within a few 
hours! ... But because corals are colonial, the size of a colony can be much larger
: big ... of thousands of these starfish, with most of the coral killed in less than a 
year. [DOC] [TLE] NOAA CoRIS - What are Coral Reefs [PAR] Dec 16, 2014 ... Coral reefs are unique (e.g., the largest structures on earth of biological ... well-
developed reefs reflect thousands of years of history (Turgeon and Asch, in press
). ... Comprising over 6,000 known species, anthozoans also include sea ... If 
these algal cells are expelled by the polyps, which can occur if the... [DOC] [TLE] O.R.G. Educational Film: - Oceanic Research Group [PAR] The reef itself is a living, growing organism- a colony of tiny animals all working ... 
Ever so slowly, over hundreds, or thousands of years, the coral polyps add ... In 
order to get additional nutrients, many corals have become symbiotic with a ... In 
time, a giant new coral reef community will arise from these humble beginnings. [DOC] [TLE] Coral Reefs - MarineBio.org [PAR] Coral reefs are built by millions of coral polyps, small colonial animals 
resembling ... and communities that contain hundreds to hundreds of thousands 
of polyps. ... Aside from their scientific utility in species identification, sclerites give 
these ... Organisms responsible for building tropical (biotic) coral reefs can only 
grow at... [DOC] [TLE] The Biology of Coral Reefs (Final) [PAR] Today, thousands of visitors armed with a snorkel or scuba gear can find 
underwater treasures as ... Depending on the species, coral polyps measure 
anywhere from a few millimeters to .... These reefs were built by colonies of 
calcareous algae, not coral (14, 16). ... They had dug back through over 5 million 
years of history. [DOC] [TLE] Coral reef - Wikipedia [PAR] Coral reefs are diverse underwater ecosystems held together by calcium 
carbonate structures secreted by corals. Coral reefs are built by colonies of tiny 
animals found in marine waters that contain few nutrients. Most coral reefs are 
built from stony corals, which in turn consist of polyps ... Most of the coral reefs we 
can see today were formed after the last glacial... [DOC] [TLE] Corals - Seattle Aquarium [PAR] You can see both warm- and cold-water corals at the Seattle Aquarium. ... these 
skeletons can build up and form massive coral reefs, with colonies ... It's 
estimated that some existing reefs began growing over 50 million years ago! ... 
more than 4,000 species of fish, 700 species of coral, and thousands of other 
plants and... [DOC] [TLE] What Are Corals? [PAR] All coral polyps have the same basic body structure including tentacles with 
stinging ... Some examples of these growth forms are branching corals, plate or ... 
Massive coral colonies like the star and brain corals pictured above can grow to 
... Coral reefs form over thousands of years as successive generations of corals 
grow... [DOC] [TLE] What's killing all the coral? | MNN - Mother Nature Network [PAR] Nov 15, 2010 ... Australia's Great Barrier Reef, the world's largest coral colony, is 440 times

Question: Over thousands of years, colonies of these marine polyps can become giant reefs
Answer: Coral