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Anthomedusae
Anthoathecata, or the athecate hydroids, are an order of hydrozoans belonging to the phylum Cnidaria. A profusion of alternate scientific names exists for this long-known, heavily discussed, and spectacular group. It has also been called Gymnoblastea and (with or without an emended ending ''-ae''), Anthomedusa, Athecata, Hydromedusa, and Stylasterina. There are about 1,200 species worldwide.Schuchert, P. (2014). Anthoathecata. Accessed through: Schuchert, P. (2014) World Hydrozoa database at http://www.marinespecies.org/hydrozoa/aphia.php?p=taxdetails&id=13551 on 2014-10-31 These hydrozoans always have a polyp stage. Their hydranths grow either solitary or in colonies. There is no firm perisarc around the polyp body. The medusae, or jellyfish, are solitary animals, with tentacles arising from the bell margin, lacking statocysts but possessing radial canals. Their gonads are on the manubrium ("handle").Bouillon, J.; Gravili, C.; Pagès, F.; Gili, J.-M.; Boero, F. (2006). An introd ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perisarc
Hydrozoa (hydrozoans; ) are a taxonomic class of individually very small, predatory animals, some solitary and some colonial, most of which inhabit saline water. The colonies of the colonial species can be large, and in some cases the specialized individual animals cannot survive outside the colony. A few genera within this class live in freshwater habitats. Hydrozoans are related to jellyfish and corals and belong to the phylum Cnidaria. Some examples of hydrozoans are the freshwater jelly (''Craspedacusta sowerbyi''), freshwater polyps ('' Hydra''), ''Obelia'', Portuguese man o' war (''Physalia physalis''), chondrophores (Porpitidae), "air fern" (''Sertularia argentea''), and pink-hearted hydroids (''Tubularia''). Anatomy Most hydrozoan species include both a polypoid and a medusoid stage in their lifecycles, although a number of them have only one or the other. For example, ''Hydra'' has no medusoid stage, while '' Liriope'' lacks the polypoid stage. Polyps The hydroi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrozoans
Hydrozoa (hydrozoans; ) are a taxonomic class of individually very small, predatory animals, some solitary and some colonial, most of which inhabit saline water. The colonies of the colonial species can be large, and in some cases the specialized individual animals cannot survive outside the colony. A few genera within this class live in freshwater habitats. Hydrozoans are related to jellyfish and corals and belong to the phylum Cnidaria. Some examples of hydrozoans are the freshwater jelly ('' Craspedacusta sowerbyi''), freshwater polyps ('' Hydra''), ''Obelia'', Portuguese man o' war (''Physalia physalis''), chondrophores (Porpitidae), " air fern" (''Sertularia argentea''), and pink-hearted hydroids ('' Tubularia''). Anatomy Most hydrozoan species include both a polypoid and a medusoid stage in their lifecycles, although a number of them have only one or the other. For example, ''Hydra'' has no medusoid stage, while '' Liriope'' lacks the polypoid stage. Polyps The hydroi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kunstformen Der Natur
(known in English as ''Art Forms in Nature'') is a book of lithographic and halftone prints by German biologist Ernst Haeckel. Publication Originally published in sets of ten between 1899 and 1904 and collectively in two volumes in 1904, it consists of 100 prints of various organisms, many of which were first described by Haeckel himself. Over the course of his career, over 1000 engravings were produced based on Haeckel's sketches and watercolors; many of the best of these were chosen for , translated from sketch to print by lithographer Adolf Giltsch. A second edition of , containing only 30 prints, was produced in 1914. Themes According to Haeckel scholar Olaf Breidbach, the work was "not just a book of illustrations but also the summation of his view of the world." The over-riding themes of the plates are symmetry and le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pandeidae
Pandeidae is a family of hydroids in the class Hydrozoa. Like other jellyfish there is usually a mature medusa form which is pelagic and reproduces sexually and a hydroid or polyp form which is often benthic and reproduces asexually by budding. Characteristics Members of this family have bell-shaped medusae with a four-part manubrium or sub-umbrella, a mouth with four plain or pleated lips and four, often broad, radial canals. The gonads are smooth or folded and positioned on the walls of the manubrium and sometimes extend onto the radial canals. There are fine, hollow tentacles along the margin of the bell, mostly growing from small carrot-shaped bulbs. The hydroids have threadlike tentacles. Marine Species Identification Portal. Retrieved 2011-10-10. G ...
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Jellyfish
Jellyfish and sea jellies are the informal common names given to the medusa-phase of certain gelatinous members of the subphylum Medusozoa, a major part of the phylum Cnidaria. Jellyfish are mainly free-swimming marine animals with umbrella-shaped bells and trailing tentacles, although a few are anchored to the seabed by stalks rather than being mobile. The bell can pulsate to provide propulsion for highly efficient locomotion. The tentacles are armed with stinging cells and may be used to capture prey and defend against predators. Jellyfish have a complex life cycle; the medusa is normally the sexual phase, which produces planula larvae that disperse widely and enter a sedentary polyp phase before reaching sexual maturity. Jellyfish are found all over the world, from surface waters to the deep sea. Scyphozoans (the "true jellyfish") are exclusively marine, but some hydrozoans with a similar appearance live in freshwater. Large, often colorful, jellyfish are common in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Statocyst
The statocyst is a balance sensory receptor present in some aquatic invertebrates, including bivalves, cnidarians, ctenophorans, echinoderms, cephalopods, and crustaceans. A similar structure is also found in '' Xenoturbella''. The statocyst consists of a sac-like structure containing a mineralised mass (statolith) and numerous innervated sensory hairs ( setae). The statolith's inertia causes it to push against the setae when the animal accelerates. Deflection of setae by the statolith in response to gravity activates neurons, providing feedback to the animal on change in orientation and allowing balance to be maintained. In other words, the statolith shifts as the animal moves. Any movement large enough to throw the organism off balance causes the statolith to brush against tiny bristles which in turn send a message to the brain to correct its balance. It may have been present in the common ancestor of cnidarians and bilaterians. Hearing In cephalopods like squids, sta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radial Canal
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Gonad
A gonad, sex gland, or reproductive gland is a mixed gland that produces the gametes and sex hormones of an organism. Female reproductive cells are egg cells, and male reproductive cells are sperm. The male gonad, the testicle, produces sperm in the form of spermatozoa. The female gonad, the ovary, produces egg cells. Both of these gametes are haploid cells. Some hermaphroditic animals have a type of gonad called an ovotestis. Evolution It is hard to find a common origin for gonads, but gonads most likely evolved independently several times. Regulation The gonads are controlled by luteinizing hormone and follicle-stimulating hormone, produced and secreted by gonadotropes or gonadotrophins in the anterior pituitary gland. This secretion is regulated by gonadotropin-releasing hormone produced in the hypothalamus. Development Gonads start developing as a common primordium (an organ in the earliest stage of development), in the form of genital ridges, which are on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eudendriidae
Eudendriidae is a taxonomic family of hydroids (Hydrozoa). The family contains around 85 species. Genera *''Eudendrium ''Eudendrium'' is a large genus of hydroids (Hydrozoa), one of two in the family Eudendriidae. These animals are marine cnidarias in the family Eudendriidae. Species Species so far described in this genus include: Retrieved July 5, 2012 References External links *[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laingiidae
Magapiidae is a family of cnidarians belonging to the order Anthoathecata Anthoathecata, or the athecate hydroids, are an order of hydrozoans belonging to the phylum Cnidaria. A profusion of alternate scientific names exists for this long-known, heavily discussed, and spectacular group. It has also been called Gymnobl .... Genera: * '' Fabienna'' Schuchert, 1996 * '' Kantiella'' Bouillon, 1978 * '' Magapia'' Schuchert & Bouillon, 2009 References Filifera Cnidarian families {{Anthoathecata-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cnidae
A cnidocyte (also known as a cnidoblast or nematocyte) is an explosive cell containing one large secretory organelle called a cnidocyst (also known as a cnida () or nematocyst) that can deliver a sting to other organisms. The presence of this cell defines the phylum Cnidaria (corals, sea anemones, hydrae, jellyfish, etc.). Cnidae are used to capture prey and as a defense against predators. A cnidocyte fires a structure that contains a toxin within the cnidocyst; this is responsible for the stings delivered by a cnidarian. Structure and function Each cnidocyte contains an organelle called a cnida, cnidocyst, nematocyst, ptychocyst or spirocyst. This organelle consists of a bulb-shaped capsule containing a coiled hollow tubule structure attached to it. An immature cnidocyte is referred to as a cnidoblast or nematoblast. The externally oriented side of the cell has a hair-like trigger called a cnidocil, which is a mechano- and chemo-receptor. When the trigger is activated, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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