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Octocorals
Octocorallia (also known as Alcyonaria) is a class of Anthozoa comprising around 3,000 species of water-based organisms formed of colonial polyps with 8-fold symmetry. It includes the blue coral, soft corals, sea pens, and gorgonians (sea fans and sea whips) within three orders: Alcyonacea, Helioporacea, and Pennatulacea. These organisms have an internal skeleton secreted by mesoglea and polyps with eight tentacles and eight mesentaries. As with all Cnidarians these organisms have a complex life cycle including a motile phase when they are considered plankton and later characteristic sessile phase. Octocorals have existed at least since the Ordovician period, as shown by Maurits Lindström's findings in the 1970s, however recent work has shown a possible Cambrian origin. Biology Octocorals resemble the stony corals in general appearance and in the size of their polyps, but lack the distinctive stony skeleton. Also unlike the stony corals, each polyp has only eight tentacles, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soft Coral
Alcyonacea, or soft corals, are an order of corals. In addition to the fleshy soft corals, the order Alcyonacea now contains all species previously known as "gorgonian corals", that produce a more or less hard skeleton, though quite different from "true" corals (Scleractinia). These can be found in suborders Holaxonia, Scleraxonia, and Stolonifera. They are Sessility (zoology), sessile colony (biology), colonial cnidarians that are found throughout the oceans of the world, especially in the deep sea, polar waters, tropics and subtropics. Common names for subsets of this order are sea fans and sea whips; others are similar to the sea pens of related order Pennatulacea. Individual tiny polyp (zoology), polyps form colonies that are normally erect, flattened, branching, and reminiscent of a fan (implement), fan. Others may be whiplike, bushy, or even encrusting. A colony can be several feet high and across, but only a few inches thick. They may be brightly coloured, often purple, r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Pen
Sea pens are colonial marine cnidarians belonging to the order Pennatulacea. There are 14 families within the order; 35 extant genera, and it is estimated that of 450 described species, around 200 are valid. Sea pens have a cosmopolitan distribution, being found in tropical and temperate waters worldwide, as well as from the intertidal to depths of more than 6100 m. Sea pens are grouped with the octocorals, together with sea whips ('' gorgonians''). Although the group is named for its supposed resemblance to antique quill pens, only sea pen species belonging to the suborder Subselliflorae live up to the comparison. Those belonging to the much larger suborder Sessiliflorae lack feathery structures and grow in club-like or radiating forms. The latter suborder includes what are commonly known as sea pansies. The earliest accepted fossils are known from the Cambrian-aged Burgess Shale (''Thaumaptilon''). Similar fossils from the Ediacaran (ala ''Charnia'') may ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alcyonacea
Alcyonacea, or soft corals, are an order of corals. In addition to the fleshy soft corals, the order Alcyonacea now contains all species previously known as "gorgonian corals", that produce a more or less hard skeleton, though quite different from "true" corals (Scleractinia). These can be found in suborders Holaxonia, Scleraxonia, and Stolonifera. They are sessile colonial cnidarians that are found throughout the oceans of the world, especially in the deep sea, polar waters, tropics and subtropics. Common names for subsets of this order are sea fans and sea whips; others are similar to the sea pens of related order Pennatulacea. Individual tiny polyps form colonies that are normally erect, flattened, branching, and reminiscent of a fan. Others may be whiplike, bushy, or even encrusting. A colony can be several feet high and across, but only a few inches thick. They may be brightly coloured, often purple, red, or yellow. Photosynthetic gorgonians can be successfully kept in c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helioporacea
Helioporacea is an order of the subclass Octocorallia that forms massive lobed crystalline calcareous skeletons in colonial corals. These corals first appeared in the Cretaceous period. It consists of two families, Helioporidae Moseley, 1876Moseley, H. N. (1876). On the structure and relations of the alcyonarian ''Heliopora caerula'', with some account of the anatomy of a species of ''Sarcophyton'', notes on the structure of species of the genera ''Millepora'', ''Pocillopora'', and ''Stylaster'', and remarks on the affinities of certain palaeozoic corals. ''Philosophical Transactions of the Royal Society of London'', 166, 91–129. and Lithotelestidae Bayer & Muzik, 1977.Bayer, F. M. & Muzik, K. M. (1977). An Atlantic helioporan coral (Coelenterata: Octocorallia). ''Proceedings of the Biological Society of Washington'', 90(4), 975–984. The blue coral (''Heliopora coerulea''), the only extant species in the family Helioporidae, is most common in shallow water of the tropical Pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ordovician
The Ordovician ( ) is a geologic period and System (geology), system, the second of six periods of the Paleozoic Era (geology), Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period million years ago (Mya) to the start of the Silurian Period Mya. The Ordovician, named after the Celtic Britons, Welsh tribe of the Ordovices, was defined by Charles Lapworth in 1879 to resolve a dispute between followers of Adam Sedgwick and Roderick Murchison, who were placing the same Rock (geology), rock beds in North Wales in the Cambrian and Silurian systems, respectively. Lapworth recognized that the fossil fauna in the disputed Stratum, strata were different from those of either the Cambrian or the Silurian systems, and placed them in a system of their own. The Ordovician received international approval in 1960 (forty years after Lapworth's death), when it was adopted as an official period of the Paleozoic Era by the International Union of Geological Sciences, Intern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cnidaria
Cnidaria () is a phylum under kingdom Animalia containing over 11,000 species of aquatic animals found both in freshwater and marine environments, predominantly the latter. Their distinguishing feature is cnidocytes, specialized cells that they use mainly for capturing prey. Their bodies consist of mesoglea, a non-living jelly-like substance, sandwiched between two layers of epithelium that are mostly one cell thick. Cnidarians mostly have two basic body forms: swimming medusae and sessile polyps, both of which are radially symmetrical with mouths surrounded by tentacles that bear cnidocytes. Both forms have a single orifice and body cavity that are used for digestion and respiration. Many cnidarian species produce colonies that are single organisms composed of medusa-like or polyp-like zooids, or both (hence they are trimorphic). Cnidarians' activities are coordinated by a decentralized nerve net and simple receptors. Several free-swimming species of Cubozoa and Scyphozo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coenenchyme
Coenenchyme is the common tissue that surrounds and links the polyps in octocorals. It consists of mesoglea penetrated by tubes (''solenia'') and canals of the gastrodermis and contains sclerites, microscopic mineralised spicules of silica or of calcium carbonate. The outer layer of the coenenchyme is made of columnar or squamous epithelial cells, and can be covered in microvilli. The stiff projecting portion of coenenchyme that surrounds each polyp is usually reinforced by modified sclerites and is called the calyx, a term borrowed from botany. The solenia circulate nutrients throughout the coenenchyme. Coenosarc In corals, the coenosarc is the living tissue overlying the stony skeletal material of the coral. It secretes the coenosteum, the layer of skeletal material lying between the corallites (the stony cups in which the polyps sit). The coensarc is comp ... is an alternative name. References {{reflist Cnidarian anatomy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesoglea
Mesoglea refers to the extracellular matrix found in cnidarians like coral or jellyfish that functions as a hydrostatic skeleton. It is related to but distinct from mesohyl, which generally refers to extracellular material found in sponges. Description The mesoglea is mostly water. Other than water, the mesoglea is composed of several substances including fibrous proteins, like collagen and heparan sulphate proteoglycans. The mesoglea is mostly acellular, but in both cnidaria and ctenophora the mesoglea contains muscle bundles and nerve fibres. Other nerve and muscle cells lie just under the epithelial layers. The mesoglea also contains wandering amoebocytes that play a role in phagocytosing debris and bacteria. These cells also fight infections by producing antibacterial chemicals. The mesoglea may be thinner than either of the cell layers in smaller coelenterates like a hydra or may make up the bulk of the body in larger jellyfish. The mesoglea serves as an internal skeleton, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epidermis (zoology)
In zoology, the epidermis is an epithelium (sheet of cells) that covers the body of a eumetazoan (animal more complex than a sponge). Eumetazoa have a cavity lined with a similar epithelium, the gastrodermis, which forms a boundary with the epidermis at the mouth. Sponges have no epithelium, and therefore no epidermis or gastrodermis. The epidermis of a more complex invertebrate is just one layer deep, and may be protected by a non-cellular cuticle. The epidermis of a higher vertebrate has many layers, and the outer layers are reinforced with keratin Keratin () is one of a family of structural fibrous proteins also known as ''scleroproteins''. Alpha-keratin (α-keratin) is a type of keratin found in vertebrates. It is the key structural material making up scales, hair, nails, feathers, ho ... and then die. References Animal anatomy Epithelium {{animal-anatomy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dendronephthya Klunzingeri
''Dendronephthya klunzingeri'' is a species of soft coral in the family Nephtheidae. This species is divaricate Divaricate means branching, or having separation or a degree of separation. The angle between branches is wide. In botany In botany, the term is often used to describe the branching pattern of plants. Plants are said to be divaricating when the ... with discontinuous contours. Each bundle has 10 to 12 polyps. The branching lobes have sizable bunches. References Animals described in 1888 Nephtheidae {{octocorallia-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stony Coral
Scleractinia, also called stony corals or hard corals, are marine animals in the phylum Cnidaria that build themselves a hard skeleton. The individual animals are known as polyps and have a cylindrical body crowned by an oral disc in which a mouth is fringed with tentacles. Although some species are solitary, most are colonial. The founding polyp settles and starts to secrete calcium carbonate to protect its soft body. Solitary corals can be as much as across but in colonial species the polyps are usually only a few millimetres in diameter. These polyps reproduce asexually by budding, but remain attached to each other, forming a multi-polyp colony of clones with a common skeleton, which may be up to several metres in diameter or height according to species. The shape and appearance of each coral colony depends not only on the species, but also on its location, depth, the amount of water movement and other factors. Many shallow-water corals contain symbiont unicellular organi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amoebocyte
An amebocyte or amoebocyte () is a mobile cell (moving like an amoeba) in the body of invertebrates including cnidaria, echinoderms, molluscs, tunicates, sponges and some chelicerates. They move by pseudopodia. Similarly to some of the white blood cells of vertebrates, in many species amebocytes are found in the blood or body fluid and play a role in the defense of the organism against pathogens. Depending on the species, an amebocyte may also digest and distribute food, dispose of wastes, form skeletal fibers, fight infections, and change into other cell types. Limulus amebocyte lysate, an aqueous extract of amebocytes from the Atlantic horseshoe crab (''Limulus polyphemus''), is commonly used in a test to detect bacterial endotoxins. In sponges, amebocytes, also known as archaeocytes, are cells found in the mesohyl that can transform into any of the animal's more specialized cell types. In tunicates they are blood cells and use pseudopodia to attack pathogens that enter the bloo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
