coral

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coral,

small, sedentary marine animal, related to the sea anemone but characterized by a skeleton of horny or calcareous material. The skeleton itself is also called coral. Although most corals form colonies by budding, there are some solitary corals; in both types the individual animals, called polyps, resemble the sea anemone in form.

Corals grow in warm and temperate climates and in the cold water found at greater depths, but they are most abundant in warm, shallow water; over 200 coral species are found in the Great Barrier Reef of Australia. In many shallow-water species the polyps contain unicellular plants, which may provide the high oxygen concentration required by such corals.

Stony Corals

In the large group known as stony corals, or true corals (Madreporaria), each polyp secretes a cup-shaped skeleton, the theca, around itself. Some solitary corals of that group may reach a diameter of 10 in. (25 cm); in the colonial forms the individual polyps are usually under 1-8 in. (3 mm) long, but the colonies may be enormous. The body of each polyp is saclike, consisting of a wall of jellylike material surrounding a digestive cavity, with a single opening, the mouth, at the unattached end. The mouth is surrounded by tentacles used to capture small prey and is invaginated to form a pharynx leading into the body cavity. Thin sheets of tissue (mesentaries) extend radially from the wall to the pharynx, dividing the cavity. A second set of radial divisions is created by folds (septa) of the outer skeleton and body wall, which extend upward from the floor of the body cavity. Reproduction occurs both sexually and by budding. Sexual reproduction is by means of eggs and sperm, which are produced in the mesentaries and shed into the water. Fertilization results in a free-swimming larva, which attaches to a surface and secretes a skeleton, becoming (in colonial forms) the parent of a new colony.

As new polyps are produced by budding they remain attached to each other by thin sheets of living tissue as well as by newly secreted skeletal material. The great variety in the form of various colonial corals, which may be treelike and branching, or rounded and compact, depends chiefly on the method of budding of the particular species. In the brain corals, for example, each theca merges with the one next to it on either side, forming long rows of polyps separated by deep channels. In some of the branching corals the polyps occupy small, discrete pits on the surface of the skeleton. As a colonial coral produces more polyps the lower members die and new layers are built up on the old skeleton, forming a large mass. In tropical and subtropical regions these massive corals, along with other plants and animals, may form a coral reefcoral reefs,
limestone formations produced by living organisms, found in shallow, tropical marine waters. In most reefs, the predominant organisms are stony corals, colonial cnidarians that secrete an exoskeleton of calcium carbonate (limestone).
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. Most of the reef-forming corals belong to the stony coral group.

Soft Corals

The soft corals (Alcyonaria) are a group of soft, often feathery forms, with skeletons composed of calcareous or horny particles imbedded in the body wall. Each polyp of a soft coral has eight tentacles. Among the well-known soft corals are the sea pensea pen,
long, slender colonial organism of the same phylum as the jellyfish. Sea pen colonies are formed by several genera of the order Pennatulacea. The colony consists of a stalk formed by an organism called a primary polyp (see polyp and medusa) and short branches formed by
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, sea pansysea pansy,
fleshy, leaf-shaped colony of marine organisms belonging to the genus Renilla in the same phylum as the jellyfish. The colony consists of a stalk formed by a large organism called a primary polyp (see polyp and medusa) that is thrust into soft bottom material;
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, whip coral, and organpipe coral. The precious red coral (Corallium) of the Mediterranean Sea, used for jewelry, also belongs to that group. The spicules of its skeleton are fused together.

Classification

Stony and soft corals are classified in the phylum CnidariaCnidaria
or Coelenterata
, phylum of invertebrate animals comprising the sea anemones, corals, jellyfish, and hydroids. Cnidarians are radially symmetrical (see symmetry, biological).
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, class Anthozoa.

coral

[′kä·rəl]
(invertebrate zoology)
The skeleton of certain solitary and colonial anthozoan cnidarians; composed chiefly of calcium carbonate.

coral

cures madness; stanches blood from wound. [Gem Symbolism: Kunz, 68]
See: Healing

coral

1. any marine mostly colonial coelenterate of the class Anthozoa having a calcareous, horny, or soft skeleton
2. 
a. the calcareous or horny material forming the skeleton of certain of these animals
b. (as modifier): a coral reef
3. 
a. a rocklike aggregation of certain of these animals or their skeletons, forming an island or reef
b. (as modifier): a coral island
4. 
a. a deep-pink to yellowish-pink colour
b. (as adjective): a coral blouse

CORAL

(1)

CORAL

(2)
A deductive database and logic programming system based on Horn-clause rules with extensions like SQL's group-by and aggregation operators. CORAL was developed at the University of Wisconsin-Madison. It is implemented in C++ and has a Prolog-like syntax.

Many evaluation techniques are supported, including bottom-up fixpoint evaluation and top-down backtracking. Modules are separately compiled; different evaluation methods can be used in different modules within a single program. Disk-resident data is supported via an interface to the Exodus storage manager. There is an on-line help facility. It requires AT&T C++ 2.0 (or G++ soon) and runs on Decstation and Sun-4.

ftp://ftp.cs.wisc.edu/.
References in periodicals archive ?
depressa in the vicinity of La Paz, Espiritu Santo Island and Partida Island, although both species may be found living in the same coral head.
The outer reef, 50 to 100 yards from shore, has many fishes, large coral heads, turtles.
Aerial photographs at the Ocean Sports beach shack can help you locate best coral heads, 1/2 mile from shore (water is still only 10 feet deep).
I can't tell you how many times I've been away from the boat and found a large coral head or ledge that had a big boy lobster way back in his happy place.
Atlantic waters starting from a halfmile offshore to a maximum of six miles (near Key West) are riddled with ledges and coral heads in depths from 10 to 40 feet.
Lophelia coral heads have grown up over thousands of years, forming mounds a mile or two long at the base and up to 500 feet high.
It's no great secret that lobsters are most commonly found in crevices, limestone holes and under coral heads, ledges and manmade wreckage.
Huge offshore snook move inshore to spawn this month, and many of them make their first stop right at the big rockpiles and coral heads that front Round Key.
We lost a 1,000-year-old coral head off Pandora Reef in '98.
We kill these fish in a coral head before going for the lobster or grouper inside, but watch their spines.
When working around a coral head, use a short-shafted pole spear or a short-shafted spear on your sling.