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Myxozoa
Myxozoa (etymology: Greek: μύξα ''myxa'' "slime" or "mucus" + thematic vowel o + ζῷον ''zoon'' "animal") is a subphylum of aquatic cnidarian animals – all obligate parasites. It contains the smallest animals ever known to have lived. Over 2,180 species have been described and some estimates have suggested at least 30,000 undiscovered species. Many have a two-host lifecycle, involving a fish and an annelid worm or a bryozoan. The average size of a myxosporean spore usually ranges from 10 μm to 20 μm, whereas that of a malacosporean (a subclade of the Myxozoa) spore can be up to 2 mm. Myxozoans can live in both freshwater and marine habitats. Myxozoans are highly derived cnidarians that have undergone dramatic evolution from a free swimming, self-sufficient jellyfish-like creature into their current form of obligate parasites composed of very few cells – sometimes only a single cell. As myxozoans evolved into microscopic parasites, they lost many g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myxozoans Life Cycle
Myxozoa (etymology: Greek language, Greek: μύξα ''myxa'' "slime" or "mucus" + thematic vowel o + ζῷον ''zoon'' "animal") is a subphylum of aquatic cnidarian animals – all obligate parasites. It contains the smallest animals ever known to have lived. Over 2,180 species have been described and some estimates have suggested at least 30,000 undiscovered species. Many have a two-host lifecycle, involving a fish and an annelid worm or a bryozoan. The average size of a myxosporean spore usually ranges from 10 μm to 20 μm, whereas that of a malacosporean (a subclade of the Myxozoa) spore can be up to 2 mm. Myxozoans can live in both freshwater and marine habitats. Myxozoans are highly derived cnidarians that have undergone dramatic evolution from a free swimming, self-sufficient jellyfish-like creature into their current form of obligate parasites composed of very few cells – sometimes only a single cell. As myxozoans evolved into microscopic parasites, ... [...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] |
Enteromyxum Leei
''Enteromyxum leei'' is a species of myxozoan, histozoic parasite that infects the intestinal tract and sometimes associated organs, like gall bladder and liver, of several teleostean fish species. Myxozoans are microscopic metazoans, with an obligate parasitic life-style. The parasite stages of this species live in the paracelullar space between fish enterocytes. It is the causative agent of enteromyxosis, or emaciative disease, also known as "razor blade syndrome" in sparid fish. ''E. leei'' has a wide host and geographical range within marine fish (at least 60 species from 22 different families, mainly Perciforms), and even freshwater fish have been infected experimentally. ''E. leei'' initially emerged in the Mediterranean in the late 1980s and it is believed to have been unintentionally introduced into the Red Sea.Diamant, A. (1997). Fish-to-fish transmission of a marine myxosporean. Diseases of Aquatic Organisms 30, 99-105. Its pathogenicity and economic impact depend on the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myxosporea
Myxosporea is a class of microscopic parasites, belonging to the Myxozoa clade within Cnidaria. They have a complex life cycle which comprises vegetative forms in two hosts, an aquatic invertebrate (generally an annelid but sometimes a bryozoan) and an ectothermic vertebrate, usually a fish. Each host releases a different type of spore. The two forms of spore are so different that until relatively recently they were treated as belonging to different classes within the Myxozoa. Taxonomic status The taxonomy of both actinosporeans and myxosporeans was originally based on spore morphology. In 1994 the phylum Myxozoa was redefined to solve the taxonomic and nomenclatural problems arising from the two-host life cycle of myxozoans. The distinction between the two previously recognised classes Actinosporea and Myxosporea disappeared and the class ''Actinosporea'' was suppressed, becoming a synonym of the class ''Myxosporea'' (Bütschli, 1881). The generic names of actinosporeans were r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animal
Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motility, able to move, can Sexual reproduction, reproduce sexually, and go through an ontogenetic stage in which their body consists of a hollow sphere of Cell (biology), cells, the blastula, during Embryogenesis, embryonic development. Over 1.5 million Extant taxon, living animal species have been Species description, described—of which around 1 million are Insecta, insects—but it has been estimated there are over 7 million animal species in total. Animals range in length from to . They have Ecology, complex interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as zoology. Most living animal species are in Bilateria, a clade whose members have a Symmetry in biology#Bilate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myxosporea
Myxosporea is a class of microscopic parasites, belonging to the Myxozoa clade within Cnidaria. They have a complex life cycle which comprises vegetative forms in two hosts, an aquatic invertebrate (generally an annelid but sometimes a bryozoan) and an ectothermic vertebrate, usually a fish. Each host releases a different type of spore. The two forms of spore are so different that until relatively recently they were treated as belonging to different classes within the Myxozoa. Taxonomic status The taxonomy of both actinosporeans and myxosporeans was originally based on spore morphology. In 1994 the phylum Myxozoa was redefined to solve the taxonomic and nomenclatural problems arising from the two-host life cycle of myxozoans. The distinction between the two previously recognised classes Actinosporea and Myxosporea disappeared and the class ''Actinosporea'' was suppressed, becoming a synonym of the class ''Myxosporea'' (Bütschli, 1881). The generic names of actinosporeans were r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spore
In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, fungi and protozoa. Bacterial spores are not part of a sexual cycle, but are resistant structures used for survival under unfavourable conditions. Myxozoan spores release amoeboid infectious germs ("amoebulae") into their hosts for parasitic infection, but also reproduce within the hosts through the pairing of two nuclei within the plasmodium, which develops from the amoebula. In plants, spores are usually haploid and unicellular and are produced by meiosis in the sporangium of a diploid sporophyte. Under favourable conditions the spore can develop into a new organism using mitotic division, producing a multicellular gametophyte, which eventually goes on to produce gametes. Two gametes fuse to form a zygote which develops into a new s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetracapsuloides Bryosalmonae
''Tetracapsuloides bryosalmonae'' is a myxozoan parasite of salmonid fish. It is the only species currently recognized in the monotypic genus ''Tetracapsuloides''. It is the cause of proliferative kidney disease (PKD), one of the most serious parasitic diseases of salmonid populations in Europe and North America that can result in losses of up to 90% in infected populations. Taxonomy Until the late 1990s, the organism which caused PKD was enigmatic, thus called PKX organism. The causative agent of PKD was recognized as a form of Malacosporean, but the absence of mature spores in salmonid hosts, the lack of fish to fish transmission, and seasonality of the disease suggested that the life cycle of PKX was completed in another host and that infection of salmonids could be accidental. Korotneff observed a myxozoan in the bryozoan, '' Plumatella fungosa'', in 1892, which he described as ''Myxosporidium bryozoides.'' Myxozoan infection of bryozoans was not reported again until 1996. Eco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proliferative Kidney Disease
''Tetracapsuloides bryosalmonae'' is a myxozoan parasite of salmonid fish. It is the only species currently recognized in the monotypic genus ''Tetracapsuloides''. It is the cause of proliferative kidney disease (PKD), one of the most serious parasitic diseases of salmonid populations in Europe and North America that can result in losses of up to 90% in infected populations. Taxonomy Until the late 1990s, the organism which caused PKD was enigmatic, thus called PKX organism. The causative agent of PKD was recognized as a form of Malacosporean, but the absence of mature spores in salmonid hosts, the lack of fish to fish transmission, and seasonality of the disease suggested that the life cycle of PKX was completed in another host and that infection of salmonids could be accidental. Korotneff observed a myxozoan in the bryozoan, '' Plumatella fungosa'', in 1892, which he described as ''Myxosporidium bryozoides.'' Myxozoan infection of bryozoans was not reported again until 1996. Eco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Henneguya Ictaluri
''Henneguya'' is a genus of myxosporean parasites belonging to the family Myxobolidae. The species of this genus are found in Europe and America. Species according to GBIF (except ''H. adherens''): * '' Henneguya adherens'' Azevedo & MatosCarlos Azevedo, Edilson Matos''Henneguya adherens'' n. sp. (Myxozoa, Myxosporea), parasite of the Amazonian fish, ''Acestrorhynchus falcatus'' In: J Eukaryot Microbiol 42(5). Sep-Oct 1995; pp515-518. doi:10.1111/j.1550-7408.1995.tb05898.x. PMID 7581326 * '' Henneguya akule'' Work, Takata, Whipps & Kent, 2008 * '' Henneguya amazonica'' Rocha, Matos & Azevedo, 1992 * '' Henneguya brachideuteri'' Kpatcha, Faye, Diebakate, Fall & Toguebaye, 1997 * '' Henneguya clariae'' Abolarin, 1971 * '' Henneguya clini'' Reed, Basson, Van As & Dykova, 2007 * '' Henneguya creplini'' (Gurley, 1894) * '' Henneguya doori'' Guilford, 1963 * '' Henneguya friderici'' Casal, Matos & Azevedo, 2003 * '' Henneguya garavelli'' Martins & Onaka, 2006 * '' Henneguya joalensis' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parasite
Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has characterised parasites as "predators that eat prey in units of less than one". Parasites include single-celled protozoans such as the agents of malaria, sleeping sickness, and amoebic dysentery; animals such as hookworms, lice, mosquitoes, and vampire bats; fungi such as Armillaria mellea, honey fungus and the agents of ringworm; and plants such as mistletoe, dodder, and the Orobanchaceae, broomrapes. There are six major parasitic Behavioral ecology#Evolutionarily stable strategy, strategies of exploitation of animal hosts, namely parasitic castration, directly transmitted parasitism (by contact), wikt:trophic, trophicallytransmitted parasitism (by being eaten), Disease vector, vector-transmitted parasitism, parasitoidism, and micropreda ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ectoproct
Bryozoa (also known as the Polyzoa, Ectoprocta or commonly as moss animals) are a phylum of simple, aquatic invertebrate animals, nearly all living in sedentary colonies. Typically about long, they have a special feeding structure called a lophophore, a "crown" of tentacles used for filter feeding. Most marine bryozoans live in tropical waters, but a few are found in oceanic trenches and polar waters. The bryozoans are classified as the marine bryozoans (Stenolaemata), freshwater bryozoans (Phylactolaemata), and mostly-marine bryozoans (Gymnolaemata), a few members of which prefer brackish water. 5,869living species are known. At least two genera are solitary (''Aethozooides'' and ''Monobryozoon''); the rest are colonial. The terms Polyzoa and Bryozoa were introduced in 1830 and 1831, respectively. Soon after it was named, another group of animals was discovered whose filtering mechanism looked similar, so it was included in Bryozoa until 1869, when the two groups were no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
