Coral+Colonies

   Coral colonies require a series of complicated events and circumstances to develop into the characteristically intricate reef structures for which they are known. These events and circumstances involve physical and chemical processes as well as delicate interactions among various animals and plants for coral colonies to thrive. The basic element in the development of coralline reef structures is a group of animals from the Anthozoa class, called stony corals, that is closely related to jellyfish and sea anemones. These small polyps (the individual animals that make the coral reef), which are for the most part only a fraction of an inch in length, live in colonies made up of an immeasurable number of polyps clustered together. Each individual polyp obtains calcium from the seawater where it lives to create a skeleton around the lower part of its body, and the polyps attach themselves both to the living tissue and to the external skeletons of other polyps. Many polyps tend to retreat inside of their skeletons during hours of daylight and then stretch partially outside of their</range id="566267801_6"> skeletons during hours of darkness to feed from minute plankton from the water around them. The mouth at the top of each body is surrounded by rings of tentacles used to grab onto food, and those rings of tentacles make the polyps look like flowers with rings of clustered petals; because of this, biologists <range type="comment" id="566267801_7">for years thought that </range id="566267801_7">corals were plants <range type="comment" id="566267801_8">rather than</range id="566267801_8"> animals. Once these coralline structures are established, they reproduce very quickly. They build in upward and outward directions to create a fringe of living coral surrounding the skeletal remnants of once-living coral. That coralline structures are <range type="comment" id="566267801_9">commonplace</range id="566267801_9"> in tropical waters around the world is due to the fact that they reproduce so quickly rather than the fact that they are hardy life-forms easily able to withstand external forces of nature. They cannot survive in water <range type="comment" id="566267801_10">that is too dirty</range id="566267801_10">, and they need water that is at least 72◦ F or 22◦ C to exist, so they are formed only in waters ranging from 30◦ north to 30◦ south of the equator. <range type="comment" id="566267801_11">They need a significant amount of</range id="566267801_11"> sunlight, so they live only within an area between the surface of the ocean and a few meters beneath it. In addition, they require specific types of microscopic algae for their existence and their skeletal shells <range type="comment" id="566267801_12">are delicate in nature and are easily damaged </range id="566267801_12">or fragmented. They are also prey to other sea animals<range type="comment" id="566267801_13"> such as</range id="566267801_13"> sponges and clams that bore into their skeletal structures and weaken them. Coral colonies cannot build reef structures <range type="comment" id="566267801_14">without</range id="566267801_14"> considerable assistance. The many openings in and among the skeletons must be filled in and cemented together by material from around the colonies. The filling material often consists of fine sediments created from the borings and waste of other animals around the coral or from the skeletons, shells and remnants of dead plants and animals. The material <range type="comment" id="566267801_15">that is used to cement </range id="566267801_15">the coral reefs <range type="comment" id="566267801_16">comes from </range id="566267801_16">algae and other microscopic forms of seaweed.<range type="comment" id="566267801_17"> An additional part of</range id="566267801_17"> the process of reef formation is the ongoing compaction and cementation that occurs <range type="comment" id="566267801_18">throughout</range id="566267801_18"> the process. Because of the soluble and delicate nature of the material of which coral is created, the relatively unstable crystals of corals and shells break down over time and are then rearranged <range type="comment" id="566267801_19">as a more stable form of</range id="566267801_19"> limestone. The coralline structures that are created through these complicated processes are extremely variable in form. They may, for example, be tree like and branching, or they may have more rounded and compact shapes. What they share in common, however is the extraordinary variety of plant and animal life-forms that are a necessary part of the ongoing process of their formation. =<span style="color: #0c468a; font-family: ArvoRegular,Arial,Helvetica,sans-serif; font-size: 26px;">What are corals? Listen [|HERE] = <span style="background-color: #ffffff; color: #3e3e3e; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 14px;">  Anatomy of a polyp (Source: NOAA)

<span style="background-color: #ffffff; color: #3e3e3e; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 14px;"> <span style="background-color: #ffffff; color: #3e3e3e; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 14px;">

<span style="background-color: #ffffff; color: #53555a; font-family: 'Trebuchet MS',Trebuchet,Arial,Geneva,sans-serif; font-size: 12px;"> Anemones … <span style="background-color: #ffffff; color: #3e3e3e; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 14px;"> <span style="background-color: #ffffff; color: #3e3e3e; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 14px;"> From tidal pools on rocky shores to the depths of the oceans live beautiful flowerlike animals—the sea anemones. When the tide is out <span style="background-color: #74c62c; color: #3e3e3e; font-family: Arial,Helvetica,sans-serif; font-size: 14px;">they look like sodden lumps of jelly, but as the water flows over <span style="background-color: #38d830; color: #3e3e3e; font-family: Arial,Helvetica,sans-serif; font-size: 14px;">them they expand into strange and lovely forms. Many kinds are found on both coasts of North America, but those in tropical waters are the most brilliantly colored. <span style="background-color: #ffffff; color: #3e3e3e; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 14px;"> <span style="background-color: #ffffff; color: #3e3e3e; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 14px;">media type="custom" key="27935655"