Prison15pike: Die Seite wurde neu angelegt: „[http://blog.stevenwsmeltzer.com/what-are-coral-reefs/introduction-to-the-underwater-world/ What Are Coral Reefs] - Introduction to the Underwater World [http://…“

2013-03-30T03:52:35Z

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

Neue Seite

[http://blog.stevenwsmeltzer.com/what-are-coral-reefs/introduction-to-the-underwater-world/ What Are Coral Reefs] - Introduction to the Underwater World
[http://blog.stevenwsmeltzer.com/what-are-coral-reefs/ Coral reefs] consist of tiny animals which belong to 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 jellyfish, sea pansies, sea anemones and sea fans. Corals, subsequent to their larvae stage, aren't mobile but rather stay permanently in one place. This type of animal is called a sessile animal.

[http://www.stevenwsmeltzer.com Coral reef] colonies are made of millions of these very small, cup-shaped animals termed polyps. A solitary coral polyp might be as big as a saucer or smaller than the head of a pin. Millions of polyps working together in a collaborative colony generation after generation create the limestone skeletons that create the framework of the wonderful coral reef. Corals begin life in tropical waters as free-floating larvae. Following a relatively short period of time, the larva eventually attaches itself to a hard surface and turns into a polyp. Coral reef colonies reproduce both sexually and asexually. In sexual reproduction, the coral polyps release both eggs and sperm in the water. (This is also called coral spawning.) One kind of asexual reproduction happens when fragments of coral are broken off as a consequence of storm storms. The broken pieces of corals more often than not survive and continue to grow and make a new colony. This process is referred to as "fragmentation". Corals live 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 uniform foundation or substrate for the colony. This skeleton provides two fundamental functions, first for the coral itself it offers safety, as the polyps can contract into the structure if predators draw near and second this same skeletal construction is what creates the coral reefs over time. The calcium carbonate is produced at the base of the polyps, consequently the living portion of the coral colony occurs at the surface of the skeletal structure, totally covering it. The calcium carbonate deposited by the colony continually adds to the dimensions of the general structure and thus the growth of the reef. The growth of these coral reef structures differs greatly, based on the species of coral and environmental conditions-- ranging from 0.3 to 10 centimeters per year. The skeletons of stony corals are secreted by the lower portion of the polyp. This process produces a cup, called the calice, in which the polyp rests. The walls around the cup are called the theca, and the floor is called the basal plate. Thin, calcareous septa (sclerosepta), which give structural integrity, shelter, and an increased surface area for the polyp's soft tissues, extend upward from the basal plate and radiate inward from its outer wall. Periodically, a polyp will raise up off its base and secrete a new floor to its cup, forming a new basal plate just above the old one. This produces a tiny chamber in the skeleton. If polyps are physically stressed or under possible attack, they contract into the calice so that almost no part is exposed above the skeletal platform. This protects the organism from predators and the elements (Barnes, R.D., 1987; Sumich, 1996). Different species of coral build structures of different dimensions and shapes such as brain corals, fan corals, encrusting corals, etc., making fantastic diversity and complexity in the coral reef ecosystem. Various coral species tend to be segregated into characteristic zones on a reef, separated out by competition with other varieties along with environmental conditions. Corals have only a limited level of organ development and consists of three basic tissue layers: an external layer or epidermis, an inner layer of cells lining the gastrovascular cavity (an internal space for digestion) and a layer known as the mesoglea in between the other two layers Barnes, R.D., 1987. Corals feed by reaching out by means of tentacles to seize prey 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: Coral Reef Images Pictures of Fish Sea Turtles Crustaceans and Echinoderms Moray Eels Detailed Information on select Marine Species: Caribbean Fish Hawaiian Fish Sponges Crustaceans, Invertebrates, Mollusks, Echinoderms

What Are Coral Reefs - Versionsgeschichte

Prison15pike: Die Seite wurde neu angelegt: „[http://blog.stevenwsmeltzer.com/what-are-coral-reefs/introduction-to-the-underwater-world/ What Are Coral Reefs] - Introduction to the Underwater World [http://…“