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Anthomedusae
Anthoathecata, or the athecate hydroids, are an order (biology), order of hydrozoans belonging to the phylum (biology), phylum Cnidaria. A profusion of alternate scientific names exists for this long-known and heavily discussed 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 (zoology), polyp stage. Their wiktionary:hydranth, hydranths grow either solitary or in colonies. There is no firm perisarc around the polyp body. The medusa (biology), 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").Bou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pandeidae
Pandeidae is a family (biology), family of Anthomedusae, hydroids in the Class (biology), class Hydrozoa. Like other jellyfish there is usually a mature Medusa (biology), medusa form which is pelagic and reproduces sexually and a hydroid or polyp (zoology), polyp form which is often benthic and reproduces Asexual reproduction, 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 hydroid (zoology), hydroids have threadlike tentacles. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perisarc
Hydrozoa (hydrozoans; from Ancient Greek ('; "water") and ('; "animals")) is 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, which also 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), and pink-hearted hydroids (''Tubularia''). Anatomy Most hydrozoan species include both a polypoid and a medusoid stage in their life cycles, although a number of them have only one or the other. For example, ''Hydra'' has no medusoid stage, while '' Liriope'' lacks the polypoid stage ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Limnomedusae
Limnomedusae is an order of hydrozoans. Taxonomy The taxon was erected by Danish marine biologist Paul Lassenius Kramp in 1938 to accommodate certain families of hydrozoans with biphasic life histories. It includes genera with medusae with ecto-endodermal statocysts and with gonads alongside their radial canals, and also genera which have polyps that are not covered by a theca In biology, a theca (: thecae) is a sheath or a covering. Botany In botany, the theca is related to plant's flower anatomy. The theca of an angiosperm consists of a pair of microsporangia that are adjacent to each other and share a common ar .... Molecular analysis performed by Collins in 2006 has since shown that the Limnomedusae are not monophylic. The family Armorhydridae, which contains a single genus and a single species, '' Armorhydra janowiczi'', is found living in coarse sediment, has hollow tentacles and has no radial canals. It seems to share few morphological features with the other fa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leptomedusae
Leptothecata, or thecate hydroids, are an order of hydrozoans in the phylum Cnidaria. Their closest living relatives are the athecate hydroids, which are similar enough to have always been considered closely related, and the very apomorphic Siphonophorae, which were placed outside the "Hydroida". Given that there are no firm rules for synonymy for high-ranked taxa, alternative names like Leptomedusa, Thecaphora or Thecata, with or without the ending emended to "-ae", are also often used for Leptothecata. In the sessile stage, Leptothecata are surrounded by a chitinous outer layer as their exoskeleton, including the gonophores, their reproductive organ. Leptothecata exhibit radial symmetry, and their gonads can be found in the radial canals of the medusa stage. Their habits range from benthic to planktonic. The polyps and colonial forms are benthic, whilst the medusae are planktonic. Leptothecata exhibit extensive, complex variation. Thecata colonies also have extensive specializ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stylaster Californicus 2
''Stylaster'' is a genus of Hydrozoa, hydroids in the family (biology), family Stylasteridae. Species The following species are classed in this genus: * ''Stylaster alaskanus'' Fisher, 1938 * ''Stylaster amphiheloides'' Kent, 1871 * ''Stylaster antillarum'' Zibrowius & Cairns, 1982 * †''Stylaster antiquus'' Sismondi, 1871 * ''Stylaster asper'' Kent, 1871 * ''Stylaster atlanticus'' Broch, 1936 * ''Stylaster aurantiacus'' Cairns, 1986 * ''Stylaster bellus'' (Dana, 1848) * ''Stylaster bilobatus'' Hickson & England, 1909 * ''Stylaster bithalamus'' Broch, 1936 * ''Stylaster blatteus'' (Boschma, 1961) * ''Stylaster bocki'' Broch, 1936 * ''Stylaster boreopacificus'' Broch, 1932 * ''Stylaster boschmai'' (Eguchi, 1965) * ''Stylaster brochi'' (Fisher, 1938) * ''Stylaster brunneus'' Boschma, 1970 * ''Stylaster californicus'' (Verrill, 1866) * ''Stylaster campylecus'' (Fisher, 1938) * ''Stylaster carinatus'' Broch, 1936 * †''Stylaster chibaensis'' Eguchi, 1954 * ''Stylaster cocosensis' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nematocyst
A cnidocyte (also known as a cnidoblast) is a type of cell containing a large secretory organelle called a ''cnidocyst'', that can deliver a sting to other organisms as a way to capture prey and defend against predators. A cnidocyte explosively ejects the toxin-containing cnidocyst which is responsible for the stings delivered by a cnidarian. The presence of this cell defines the phylum Cnidaria, which also includes the corals, sea anemones, hydrae, and jellyfish. Cnidocytes are single-use cells that need to be continuously replaced. Structure and function Each cnidocyte contains an organelle called a cnidocyst, which consists of a bulb-shaped capsule and a hollow, coiled tubule that is contained within. Immature cnidocytes are referred to as cnidoblasts or nematoblasts. The externally oriented side of the cell has a hair-like trigger called a cnidocil, a mechano-chemical receptor. When the trigger is activated, the tubule shaft of the cnidocyst is ejected and, in the case ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laingiidae
Magapiidae is a family of cnidarians Cnidaria ( ) is a phylum under kingdom Animalia containing over 11,000 species of aquatic invertebrates found both in fresh water, freshwater and marine environments (predominantly the latter), including jellyfish, hydroid (zoology), hydroids, ... belonging to the order Anthoathecata. 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] |
Eudendriidae
Eudendriidae is a taxonomic family of hydroids (Hydrozoa). The family contains around 85 species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), .... Genera *'' Eudendrium'' Ehrenberg, 1834 *'' Myrionema'' Pictet, 1893 Retrieved July 5, 2012 References External links *Marine Biodiversity and Ecosystem Functioning [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gonad
A gonad, sex gland, or reproductive gland is a Heterocrine gland, mixed gland and sex organ 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 Spermatozoon, spermatozoa. The female gonad, the ovary, produces egg cells. Both of these gametes are haploid cells. Some hermaphroditic animals (and some humanssee Ovotesticular syndrome) 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 (LH) and follicle-stimulating hormone (FSH), produced and secreted by gonadotropic cell, gonadotropes or gonadotrophins in the anterior pituitary gland. This secretion is regulated by gonadotropin-releasing hormone (GnRH) produced in the hypothalamus. Development The gonads develop f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radial Canal
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