The skeletons deposited by these corals and other organisms accumulate, along with sand and other debris, to form the backbone of the reef. Over tens of thousands of years, chemical and mechanical changes turn the reef into true rock (Alstyne and Paul, 1988). The body of a coral animal consists of a polyp, which is the living portion of the coral. A polyp is a hollow, cylindrical structure attached at one end to a surface, the other end is a mouth surrounded by tentacles, which gather food and can sting prey to paralyze it. Polyps live in colonies, which grow from 1 to 7 inches, depending on the species.
Coral reefs are in short terms underwater structure made from calcium carbonate secreted by corals. Coral reefs begin to form when free-swimming coral larvae attach to submerged rocks or other hard surfaces along the edges of islands or continents. This larvae are polyps that produce calcium carbonate, which turns into a hard exoskeleton that provides protection and support for the polyp's body. As a polyp grows it continues to secrete calcium carbonate, this results in that the reef keeps growing. Each polyp links itself together with other polyps to form the reef.
Ocean currents carry the larva from the stationary parent polyp to any hard, clean, silt-free surface where, if the conditions are perfect, the larva grows into a coral forming polyp, never to move again (Levin, 1999). One of the most valuable resources for coral polyps are algae. Some live on the coral skeletons, but one type in particular, zooxanthellae, lives inside the tissue of the polyps. Zooxanthellae makes up about half the weight of the fleshy polyps and are not only a valuable food resource, but they are responsible for the brilliant colors associated with coral. When coral looses these prec... ... middle of paper ... ... as Helvarg (2000), Winiarski (19998) and Warrick (1999) have the benefit of being able to describe what coral bleaching is and it’s probable causes in a much more concise and to-the-point fashion.
“Cnidarians” is Greek for “stinging nettle” (“Introduction to Cnidaria"). Phylum Cnidaria include freshwater hydra, jellyfish, and corals. Each of these invertebrates go through transitions in body forms. Jellyfish are the most unusual and complex out of the phylum. Jellyfish are in the class Scyphozoa, which means true jellyfish.
Thousands of fish and invertebrates live in association with reefs, because of the complexity. For example, in Caribbean reefs, several hundreds species of colonial invertebrates can be found living on the undersides of platy coral. It is common for a reef to have several species of snails, sixty species of coral, and many species of fish. Out of all oceanic habitats, reefs seem to have the greatest development of complex symbiotic associations. Coral reefs are very important to humans as well.
Coral Reef Ecosystems What is a coral reef? Coral reefs are the most biologically diverse marine eco-systems on earth, rivaled only by the tropical rainforests on land. Corals grow over geologic time and have been in existence about 200 million years. Corals reached their current level of diversity 50 million years ago. The delicately balanced marine environment of the coral reef relies on the interaction of hard and soft corals, sponges, anemones, snails, rays, crabs, lobsters, turtles, dolphins and other sea life.
Biology of a Squid Squids are among the most varied and unique of all invertebrates. They are mollusks of the Class Cephalopod, along with the nautilus, cuttlefish, and octopus. Squids are highly evolved, and have developed a number of traits uncommon to most other mollusks. Fossil records of cephalopods have dated back the Cambrian Period (about 600 million years ago). Structurally, squids have only small variations of a basic theme common to all cephalopods.
Most of coral reefs are located at shallow depths in tropical waters while a small portion of them can also be found in deep water. The economic value of coral reef ecosystem is huge, approximately 29.8-375 billion a year because it services to tourism, fisheries and shoreline protection. But coral reef
This allows soft corals to spread throughout large reefs like the GBR (Bastidas et al. 2001,) and also lets them colonize reefs around the world if the planulae are picked up by large ocean currents. The main element that qualifies a substrate as acceptable for a soft coral is the amount of light it receives, although water temperature and the strength of the current are also important factors.
Corals are living structures that are made out of thousands of invertebrates (Campbell, Urry, Cain, Wasserman, Minorsky, Jackson & Reece, 2011). The invertebrates that make up the coral are called polyps, which form the coral by a process called budding. Budding is where the original polyp grows a genetically identical copy of itself until its life comes to an end. A unique characteristic of corals is that the have a mutualistic relationship with zooxanthellae, which live within their tissue. Zooxanthellae are what provide coral with their wide range of colors (Campbell, Urry, Cain, Wasserman, Minorsky, Jackson & Reece, 2011).