Coral polyps - builders of reefs.

Coral reefs are a valuable ocean resource because of the beauty, variety of forms and indispensability in their ecosystem. The tropical forests of the sea, as the coral reefs are called , is perhaps the most massive and vivid expression of life in the aquatic environment.

They provide shelter for many marine inhabitants, serve as a food source for myriad organisms, form the relief of the seabed and form sections of island land. For man, coral reefs are important not only as beautiful objects of nature, which should be admired during the holidays, they also protect the coastline from large ocean waves, from their skeletons are formed important building materials - sand and limestone.

Coral ecosystems are called a pharmacy of the 21st century. Based on the useful compounds that were found in this biocenosis, many medications have been created or are under development: antibacterial, fortifying, digestive, cardiac, cosmetic, as well as medicines for the treatment of viral infections, asthma, skin cancer, arthritis.

The class of coral polyps includes more than 6 thousand main species. These marine invertebrates can be solitary or form colonies. They also differ in size, in the presence or absence of the skeleton, its forms and composition (calcareous or proteinaceous). Reef structures are also capable of forming coral polyps of the order of the Madrepores.

"Stone gardens" form not only these miniature animal organisms. Most coral polyps have a mutually beneficial relationship with unicellular algae zooxanthellae that live inside invertebrate cells. It is believed that these autotrophic protozoans also participate in the construction of the skeleton of the coral. A great role in reef formation is played by other algae - calcareous, they perform several functions: they create a reef frame, cement various damages and supply loose material. Some other animal organisms also have value for rifostroenie, namely representatives of separate families of mollusks, polychaetes and sponges.

The mechanism of feeding polyps is interesting. About 90% of the organic matter that form microscopic algae of zooxanthellae during photosynthesis is transferred to host tissues. The second type of power is external. Coral polyps can capture and absorb pre-stunned saccule sacrifice - microscopic zooplankton and small fish.

Reproduction coral polyps are capable of carrying out in two ways: sexual and asexual. The separation of male and female gametes also occurs in two ways. At the first, which is called "spawning on the air", spermatozoa and eggs in large numbers are synchronously thrown into the water column. Over the coral reef is formed a protein "cloud", which attracts many predators, feeding on plankton. Gradually larvae of polyps, planules, are carried by ocean currents. In the second method of sexual reproduction, only male sex cells enter the water , floating freely until they meet the female coral.

Asexual reproduction of these creatures is multifaceted: they can be re-enacted in several ways, crosswise to share, spread by broken fragments.

Coral reefs - a unique phenomenon of nature, beautiful and unique, but, unfortunately, very fragile. "Stone gardens" are extremely sensitive to changes in lighting, temperature, salinity and water pollution.

Human activity is one of the most serious threats to the existence of coral colonies, which in recent years have been discolored and are dying at an accelerated rate. Only joint actions of many countries of the world can stop or at least slow down this process. Recently, marine protected areas have been established in which the interaction of authorities and scientists reduces fish harvesting, and special measures are being taken to conserve reefs. Also there are world organizations that are making efforts to solve this problem, they are developing ways of artificial formation of reefs and accelerating the growth of coral polyps.