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[http://blog.stevenwsmeltzer.com/what-are-coral-reefs/introduction-to-the-underwater-world/ What Are Coral Reefs] - Learning about Coral Reefs
[http://blog.stevenwsmeltzer.com/what-are-coral-reefs/ Coral reef systems] consist of tiny marine creatures that are in the class anthozoans, the major class of organisms within the phylum cnidaria (the "c" is silent). Cnidaria has more than 6,000 recognized species of sea anemones, sea pansies, sea fans and jellyfish. Corals, subsequent to their larvae phase, are fixed in a single place and do not move. This type of animal is known as a sessile animal.

Coral reef colonies are made of millions of these very small, cup-shaped animals termed polyps. A single coral polyp may be as large as a saucer or smaller than the head of a pin. Millions of polyps functioning in concert in a collaborative colony generation after generation make the limestone skeletons that make the framework of the beautiful coral reef. [http://www.stevenwsmeltzer.com Coral reef] colonies reproduce both sexually and asexually. In sexual reproduction, the coral polyps release both eggs and sperm into the water. (This is also known as coral spawning.) One type of asexual reproduction occurs when fragments of coral are broken off because of a storm. The broken pieces of corals typically live and continue to grow and produce a new colony. This process is known as "fragmentation". Corals exist in colonies consisting of numerous individuals, each of which is called polyp. They produce a hard calcium carbonate (rock-like) skeleton, which serves as a consistent foundation or substrate for the colony. This skeleton enables two basic functions, first for the coral itself it provides protection, as the polyps can contract into the structure if predators come near and second this same skeletal structure is what creates the coral reefs over a period of time. The calcium carbonate is produced at the foot of the polyps, consequently the living portion of the coral colony occurs at the exterior of the skeletal structure, totally covering it. The calcium carbonate deposited by the living colony incessantly adds to the size of the general structure and thus the growth of the reef. The expansion of these coral reef structures differs greatly, depending on the species of coral and environmental conditions-- ranging from 0.3 to 10 centimeters per year. Different varieties of coral build structures of different sizes and shapes such as brain corals, fan corals, encrusting corals, etc., creating marvelous diversity and intricacy in the coral reef ecosystem. Different coral species tend to be segregated into characteristic zones on a reef, separated out by competition with other species and by environmental conditions. The skeletons of stony corals are secreted by the lower part of the polyp. This process creates a cup, known as the calice, where the polyp sits. The walls encircling the cup are called the theca, and the floor or base is known as the basal plate. Thin, calcareous septa (sclerosepta), that gives structural integrity, protection, and an enlarged surface area for the polyp's soft tissues, extend upward from the basal plate and radiate inward from its external wall. Periodically, a polyp will raise up off its base and secrete a new floor or base to its cup, forming a new basal plate just above the previous one. This produces a minute chamber in the skeleton. If polyps are physically stressed or under probable attack, they contract into the calice so that virtually no part is exposed beyond the skeletal platform. This protects the organism from predators and the elements (Barnes, R.D., 1987; Sumich, 1996). Corals have only a narrow level of organ development and consists of three basic tissue layers: an outer layer or epidermis, an inner layer of cells lining the gastrovascular cavity (an internal space for digestion) and a layer called the mesoglea in between the other two layers Barnes, R.D., 1987. Corals feed by reaching out by means of tentacles to grasp quarry such as small fish and planktonic animals (any drifting organisms, animal, plant, archaea or bacteria that inhabit the pelagic zone of the oceans). See Also: Creatures of the Coral Reefs Resources: Marine Species Galleries: Crustaceans and Echinoderms Moray Eels Coral Reef Images Pictures of Fish Sea Turtles Detailed Information on select Marine Species: Caribbean Fish Hawaiian Fish Sponges Crustaceans, Invertebrates, Mollusks, Echinoderms

A Synopsis of Coral Reefs - Versionsgeschichte

Kasey7eyes: Die Seite wurde neu angelegt: „[http://blog.stevenwsmeltzer.com/what-are-coral-reefs/introduction-to-the-underwater-world/ What Are Coral Reefs] - Learning about Coral Reefs [http://blog.steve…“