Close up of Acropora coral polyps open showing connecting channels and zooxanthellae
Image details
Contributor:
Portis Imaging / Alamy Stock PhotoImage ID:
CTPY3XFile size:
28.7 MB (719.3 KB Compressed download)Releases:
Model - no | Property - noDo I need a release?Dimensions:
2592 x 3872 px | 21.9 x 32.8 cm | 8.6 x 12.9 inches | 300dpiDate taken:
13 October 2008Location:
Toronto, CanadaMore information:
Acropora is a genus of small polyp stony coral in the Phylum Cnidaria.[2] Some of its species are known as table coral, elkhorn coral and staghorn coral. Over 149 species are described.[3] Acropora is one of the major reef corals responsible for building the immense calcium carbonate substructure that supports the thin living skin of a reef. Depending on the species and location, Acropora may grow as plates or slender or broad branches. Like other corals, Acropora corals are colonies of individuals known as polyps, which are about 2 mm across and share tissue and a nerve net. The polyps can withdraw back into the coral in response to movement or disturbance by potential predators, but when undisturbed they protrude slightly. The polyps typically extend further at night to help capture plankton and dissolved organic matter from the water. Acropora is most common in shallow reef environments with bright light and moderate to high water motion. Many small reef fishes live near their colonies and retreat into the thicket of branches if threatened. Zooxanthellae, symbiotic algae, live in the corals' cells and produce energy for the animals through photosynthesis. Environmental destruction has led to a dwindling of populations of Acropora, along with other coral species. Acropora is especially susceptible to bleaching when stressed. Bleaching is due to the loss of the coral's zooxanthellae, which are a golden-brown color. Bleached corals are stark white and may die if new zooxanthellae cannot be assimilated. Common causes of bleaching and coral death include pollution, abnormally warm water temperatures, increased ocean acidification, sedimentation, and eutrophication.