Anatomy of a coral polyp. Click to enlarge. In zoology, a polyp is one of five forms of individuals found in many species of cnidarians. The two are the polyp or hydroid and the medusa. Polyps are approximately cylindrical, elongated on the axis of the body. The aboral end is attached either to the substrate by means of a disc-like holdfast if the polyp is solitary, or is connected to other polyps, either directly or indirectly, if the polyp is part of a colony. The oral end bears the mouth, and is surrounded by a circlet of tentacles. Image File history File links Download high resolution version (462x670, 123 KB) Summary http://www. ...
Image File history File links Download high resolution version (462x670, 123 KB) Summary http://www. ...
Zoology (rarely spelled zoölogy) is the biological discipline which involves the study of non-human animals. ...
Classes Anthozoa — corals and sea anemones Scyphozoa — jellyfish Staurozoa — stalked jellyfish Cubozoa — sea wasps or box jellyfish Polypodiozoa Hydrozoa — hydroids, hydra-like animals Trilobozoa — extincts Cnidaria[1] (IPA: [2]) is a phylum containing some 11,000 species of relatively simple animals found exclusively in aquatic, mostly marine, environments. ...
In biology, a medusa (also known as a hydromedusa) is a form of cnidarian in which the body is shortened on its principal axis and broadened, sometimes greatly, in contrast with the hydroid or polyp. ...
It has been suggested that this article or section be merged with mouth (human). ...
Tentacles can refer to the elongated flexible organs that are present in some animals, especially invertebrates, and sometimes to the hairs of the leaves of some insectivorous plants. ...
In the class Anthozoa, comprising the sea-anemones and corals, the individual is always a polyp; in the class Hydrozoa, however, the individual may be either a polyp or a medusa, with most species undergoing a life cycle with both a polyp stage and a medusa stage. In class Scyphozoa, the medusa stage is dominant, and the polyp stage may or may not be present, depending on the family. In those scyphozoans that have the larval planula metamorphose into a polyp, the polyp, also called a "scyphistoma," grows until it develops a stack of plate-like medusae that pinch off and swim away in a process known as "strobilation." Once strobilation is complete, the polyp may die, or regenerate itself to repeat the process again later. Extant Subclasses and Orders Alcyonaria Alcyonacea Helioporacea Zoantharia Antipatharia Corallimorpharia Scleractinia Zoanthidea [1][2] See Anthozoa for details For other uses, see Coral (disambiguation). ...
Subclasses Anthomedusae Laingiomedusae Leptomedusae Limnomedusae Siphonophorae Actinulidae Narcomedusae Trachymedusae Polypodiozoa Organisms of the Class Hydrozoa belong to the phylum Cnidaria. ...
This article is about jellyfish, the sea creatures. ...
In biological classification, family (Latin: familia, plural familiae) is 1) a rank or 2) a taxon in that rank. ...
A planula is the free-swimming, flattened, ciliated, bilaterally symmetrical larva of a hydrozoan cnidarian. ...
The body of the polyp may be roughly compared in structure to a sac, the wall of which is composed of two layers of cells. The outer layer is known technically as the ectoderm, the inner layer as the endoderm (or gastroderm). Between ectoderm and endoderm is a supporting layer of structureless gelatinous substance termed mesogloea, secreted by the cell-layers of the body-wall. The mesogloea may be a very thin layer, or may reach a fair thickness, and then sometimes contains skeletal elements formed by cells which have migrated into it from the ectoderm. Organs derived from each germ layer. ...
Organs derived from each germ layer. ...
Mesoglea is the clear, inert, jellylike substance that makes up most of the bodies of jellyfish, comb jellies and certain other primitive sea creatures. ...
The sac-like body built up in this way is attached usually to some firm object by its blind end, and bears at the upper end the mouth which is surrounded by a circle of glove-finger-like tentacles. The tentacles are organs which serve both for the tactile sense and for the capture of food. By means of the stinging nettle-cells or nematocysts with which the tentacles are thickly covered, living organisms of various kinds are firmly held and at the same time paralysed or killed, and by means of longitudinal muscular fibrils formed from the cells of the ectoderm the tentacles are contracted and convey the food to the mouth. By means of circularly disposed muscular fibrils formed from the endoderm the tentacles can be protracted or thrust out after contraction. By muscle-fibres belonging to the same two systems the whole body may be retracted or protruded. Tentacles can refer to the elongated flexible organs that are present in some animals, especially invertebrates, and sometimes to the hairs of the leaves of some insectivorous plants. ...
Cnidocytes are prey-capture and defensive cells found on animals of the phylum Cnidaria. ...
We can distinguish therefore in the body of a polyp the column, circular or oval in section, forming the trunk, resting on a base or foot and surmounted by the crown of tentacles, which enclose an area termed the peristome, in the centre of which again is the mouth. As a rule there is no other opening to the body except the mouth, but in some cases excretory pores are known to occur in the foot, and pores may occur at the tips of the tentacles. Thus it is seen that a polyp is an animal of very simple structure, a living fossil that has not changed significantly for about half a billion years (per generally accepted dating of Cambrian sedimentary rock). In bryophyte mosses, the peristome is a specialed structure in the sporangium that allows for gradual spore discharge, instead of releasing them all at once. ...
This article or section does not adequately cite its references or sources. ...
The Cambrian is a major division of the geologic timescale that begins about 542 ± 1. ...
The external form of the polyp varies greatly in different cases. The column may be long and slender, or may be so short in the vertical direction that the body becomes disk-like. The tentacles may number many hundreds or may be very few, in rare cases only one or two. They may be long and filamentous, or short and reduced to mere knobs or warts. They may be simple and unbranched, or they may be feathery in pattern. The mouth may be level with the surface of the peristome, or may be projecting and trumpet-shaped. As regards internal structure, polyps exhibit two well-marked types of organization, each characteristic of one of the two classes, Hydrozoa and Anthozoa. Subclasses Anthomedusae Laingiomedusae Leptomedusae Limnomedusae Siphonophorae Actinulidae Narcomedusae Trachymedusae Polypodiozoa Organisms of the Class Hydrozoa belong to the phylum Cnidaria. ...
Extant Subclasses and Orders Alcyonaria Alcyonacea Helioporacea Zoantharia Antipatharia Corallimorpharia Scleractinia Zoanthidea [1][2] See Anthozoa for details For other uses, see Coral (disambiguation). ...
In the class Hydrozoa, the polyps are indeed often very simple, like the common little freshwater species of the genus Hydra. Anthozoan polyps, including the corals and sea anemones, are much more complex due to the development of a tubular stomodaeum leading inward from the mouth and a series of radial partitions called mesenteries. Many of the mesenteries project into the enteric cavity but some extend from the body wall to the central stomodaeum. Subclasses Anthomedusae Laingiomedusae Leptomedusae Limnomedusae Siphonophorae Actinulidae Narcomedusae Trachymedusae Polypodiozoa Organisms of the Class Hydrozoa belong to the phylum Cnidaria. ...
Species Hydra americana Hydra attenuata Hydra canadensis Hydra carnea Hydra cauliculata Hydra circumcincta Hydra hymanae Hydra littoralis Hydra magnipapillata Hydra minima Hydra oligactis Hydra oregona Hydra pseudoligactis Hydra rutgerensis Hydra utahensis Hydra viridis Hydra is a genus of simple, fresh-water animals possessing radial symmetry. ...
Extant Subclasses and Orders Alcyonaria Alcyonacea Helioporacea Zoantharia Antipatharia Corallimorpharia Scleractinia Zoanthidea [1][2] See Anthozoa for details For other uses, see Coral (disambiguation). ...
Extant Subclasses and Orders Alcyonaria Alcyonacea Helioporacea Zoantharia Antipatharia Corallimorpharia Scleractinia Zoanthidea [1][2] See Anthozoa for details For other uses, see Coral (disambiguation). ...
Families Many, see text. ...
this is the interation of. ...
In anatomy, a mesentery is a part of the peritoneum that connects an internal organ, such as the small intestine, to the abdominal wall. ...
It is an almost universal attribute of polyps to possess the power of reproducing themselves non-sexually by the method of budding. This mode of reproduction may be combined with sexual reproductiveness, or may be the sole method by which the polyp produces offspring, in which case the polyp is entirely without sexual organs. In many cases the buds formed do not separate from the parent but remain in continuity with it, thus forming colonies or stocks, which may reach a great size and contain a vast number of individuals. Slight differences in the method of budding produce great variations in the form of the colonies. The reef-building corals are polyp-colonies, strengthened by the formation of a firm skeleton. High magnification view of a budding yeast Budding is the formation of a new organism by the protrusion of part of another organism. ...
For other uses, see Reproduction (disambiguation) Reproduction is the biological process by which new individual organisms are produced. ...
A sex organ, or primary sexual characteristic, narrowly defined, is any of those parts of the body (which are not always bodily organs according to the strict definition) which are involved in sexual reproduction and constitute the reproductive system in an complex organism; namely: Male: penis (notably the glans penis...
The name polyp was given to these organisms from their supposed resemblance to an octopus (Fr. poulpe), with its circle of writhing arms round the mouth. This comparison, though far-fetched, is certainly more reasonable than the common name "coral-insects" applied to the polyps which form coral.They are star like in shape. Suborders †Pohlsepia (incertae sedis) †Proteroctopus (incertae sedis) †Palaeoctopus (incertae sedis) Cirrina Incirrina Synonyms Octopoida Leach, 1817 The octopus (Greek , eight-legs) is a cephalopod of the order Octopoda that inhabits many diverse regions of the ocean, especially coral reefs. ...
This article incorporates text from the Encyclopædia Britannica Eleventh Edition article "Polyp", a publication now in the public domain. Encyclopædia Britannica, the eleventh edition The Encyclopædia Britannica Eleventh Edition (1910–1911) is perhaps the most famous edition of the Encyclopædia Britannica. ...
The public domain comprises the body of all creative works and other knowledge—writing, artwork, music, science, inventions, and others—in which no person or organization has any proprietary interest. ...
See also
|
Feeds |
Contact