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Trichodina
Trichodina is a genus of ciliate alveolates that is ectocommensal or parasitic on aquatic animals, particularly fish. They are characterised by the presence of a ring of interlocking cytoskeletal denticles, which provide support for the cell and allow for adhesion to surfaces including fish tissue. Taxonomy Trichodinids are members of the peritrichous ciliates, a paraphyletic group within the Oligohymenophorea. Specifically, they are mobiline peritrichs because they are capable of locomotion, as opposed to sessiline peritrichs such as ''Vorticella'' and ''Epistylis'', which adhere to the substrate via a stalk or lorica. There are over 150 species in the genus ''Trichodina''. '' Trichodinella'', '' Tripartiella'', '' Hemitrichodina'', '' Paratrichodina'' and '' Vauchomia'' are similar genera. Morphology Trichodinids are round ciliates that may be disc-shaped or hemispherical. The cytostome (cell mouth) is on the surface that faces away from the host; this is termed the o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trichodinidae
Trichodinidae is a family of ciliates of the order Mobilida, class Oligohymenophorea. Members of the family are ectoparasites (or, alternatively, ectocommensals) of a wide variety of aquatic organisms, including fish, amphibians, hydrozoans, molluscs and crustaceans. Suggestion from an anonymous editor: Trichodina actually infect Hydra too, so someone needs to add that in, along with a citation. Genera The family consists of four genera. * '' Dipartiella'' Stein, 1961 * '' Paratrichodina'' Lom, 1963 * ''Trichodina Trichodina is a genus of ciliate alveolates that is ectocommensal or parasitic on aquatic animals, particularly fish. They are characterised by the presence of a ring of interlocking cytoskeletal denticles, which provide support for the cell an ...'' Ehrenberg, 1830 * '' Trichodinella'' Srámek-Husek, 1953 References * Oligohymenophorea Parasitic alveolates Ciliate families {{ciliate-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mobilida
Mobilida is a group of parasitic or symbiotic peritrich ciliates, comprising more than 280 species. Mobilids live on or within a wide variety of aquatic organisms, including fish, amphibians, molluscs, cnidarians, flatworms and other ciliates, attaching to their host organism by means of an aboral adhesive disk. Some mobilid species are pathogens of wild or farmed fish, causing severe and economically damaging diseases such as trichodinosis. Morphology and Feeding As the name suggests, mobilida cells are mobile, capable of moving about on the body of a host organism, and of swimming between hosts. This sets them apart from the predominantly sessile peritrichs of the order Sessilida, such as Vorticella and Epistylis, which, during the feeding, or vegetative, phase of the life cycle remain attached to submerged surfaces, often by means of a stalk. Like all peritrichs, the mobilids possess a spiral wreathe of cilia running counterclockwise around the oral region (peristome), at th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eukaryota
Eukaryotes () are organisms whose Cell (biology), cells have a cell nucleus, nucleus. All animals, plants, fungi, and many unicellular organisms, are Eukaryotes. They belong to the group of organisms Eukaryota or Eukarya, which is one of the Three-domain system, three domains of life. Bacteria and Archaea (both prokaryotes) make up the other two domains. The eukaryotes are usually now regarded as having emerged in the Archaea or as a sister of the Asgard (archaea), Asgard archaea. This implies that there are only Two-domain system, two domains of life, Bacteria and Archaea, with eukaryotes incorporated among archaea. Eukaryotes represent a small minority of the number of organisms, but, due to their generally much larger size, their collective global biomass (ecology), biomass is estimated to be about equal to that of prokaryotes. Eukaryotes emerged approximately 2.3–1.8 billion years ago, during the Proterozoic eon, likely as Flagellated cell, flagellated phagotrophs. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ciliate Genera
The ciliates are a group of alveolates characterized by the presence of hair-like organelles called cilia, which are identical in structure to eukaryotic flagella, but are in general shorter and present in much larger numbers, with a different undulating pattern than flagella. Cilia occur in all members of the group (although the peculiar Suctoria only have them for part of their life cycle) and are variously used in swimming, crawling, attachment, feeding, and sensation. Ciliates are an important group of protists, common almost anywhere there is water—in lakes, ponds, oceans, rivers, and soils. About 4,500 unique free-living species have been described, and the potential number of extant species is estimated at 27,000–40,000. Included in this number are many ectosymbiotic and endosymbiotic species, as well as some obligate and opportunistic parasites. Ciliate species range in size from as little as 10 µm in some colpodeans to as much as 4 mm in length in some gel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eutrophication
Eutrophication is the process by which an entire body of water, or parts of it, becomes progressively enriched with minerals and nutrients, particularly nitrogen and phosphorus. It has also been defined as "nutrient-induced increase in phytoplankton productivity". Water bodies with very low nutrient levels are termed oligotrophic and those with moderate nutrient levels are termed mesotrophic. Advanced eutrophication may also be referred to as dystrophic and hypertrophic conditions. Eutrophication can affect freshwater or salt water systems. In freshwater ecosystems it is almost always caused by excess phosphorus. In coastal waters on the other hand, the main contributing nutrient is more likely to be nitrogen, or nitrogen and phosphorus together. This depends on the location and other factors. When occurring naturally, eutrophication is a very slow process in which nutrients, especially phosphorus compounds and organic matter, accumulate in water bodies. These nutrients deriv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mollusca
Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is estimated between 60,000 and 100,000 additional species. The proportion of undescribed species is very high. Many taxa remain poorly studied. Molluscs are the largest marine phylum, comprising about 23% of all the named marine organisms. Numerous molluscs also live in freshwater and terrestrial habitats. They are highly diverse, not just in size and anatomical structure, but also in behaviour and habitat. The phylum is typically divided into 7 or 8 taxonomic classes, of which two are entirely extinct. Cephalopod molluscs, such as squid, cuttlefish, and octopuses, are among the most neurologically advanced of all invertebrates—and either the giant squid or the colossal squid is the largest known invertebrate species. The gastropod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copepod
Copepods (; meaning "oar-feet") are a group of small crustaceans found in nearly every freshwater and saltwater habitat (ecology), habitat. Some species are planktonic (inhabiting sea waters), some are benthos, benthic (living on the ocean floor), a number of species have parasitic phases, and some continental species may live in limnoterrestrial habitats and other wet terrestrial places, such as swamps, under leaf fall in wet forests, bogs, springs, ephemeral ponds, and puddles, damp moss, or water-filled recesses (phytotelmata) of plants such as bromeliads and pitcher plants. Many live underground in marine and freshwater caves, sinkholes, or stream beds. Copepods are sometimes used as Ecological indicator, biodiversity indicators. As with other crustaceans, copepods have a larval form. For copepods, the egg hatches into a Crustacean larvae#Nauplius, nauplius form, with a head and a tail but no true thorax or abdomen. The larva molts several times until it resembles the adult an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microscope
A microscope () is a laboratory instrument used to examine objects that are too small to be seen by the naked eye. Microscopy is the science of investigating small objects and structures using a microscope. Microscopic means being invisible to the eye unless aided by a microscope. There are many types of microscopes, and they may be grouped in different ways. One way is to describe the method an instrument uses to interact with a sample and produce images, either by sending a beam of light or electrons through a sample in its optical path, by detecting photon emissions from a sample, or by scanning across and a short distance from the surface of a sample using a probe. The most common microscope (and the first to be invented) is the optical microscope, which uses lenses to refract visible light that passed through a thinly sectioned sample to produce an observable image. Other major types of microscopes are the fluorescence microscope, electron microscope (both the transmi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silver Nitrate
Silver nitrate is an inorganic compound with chemical formula . It is a versatile precursor to many other silver compounds, such as those used in photography. It is far less sensitive to light than the halides. It was once called ''lunar caustic'' because silver was called ''luna'' by ancient alchemists who associated silver with the moon. In solid silver nitrate, the silver ions are three- coordinated in a trigonal planar arrangement. Synthesis and structure Albertus Magnus, in the 13th century, documented the ability of nitric acid to separate gold and silver by dissolving the silver. Indeed silver nitrate can be prepared by dissolving silver in nitric acid followed by evaporation of the solution. The stoichiometry of the reaction depends upon the concentration of nitric acid used. :3 Ag + 4 HNO3 (cold and diluted) → 3 AgNO3 + 2 H2O + NO :Ag + 2 HNO3 (hot and concentrated) → AgNO3 + H2O + NO2 The structure of silver nitrate has been examined by X-ray crystallography sever ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cilia
The cilium, plural cilia (), is a membrane-bound organelle found on most types of eukaryotic cell, and certain microorganisms known as ciliates. Cilia are absent in bacteria and archaea. The cilium has the shape of a slender threadlike projection that extends from the surface of the much larger cell body. Eukaryotic flagella found on sperm cells and many protozoans have a similar structure to motile cilia that enables swimming through liquids; they are longer than cilia and have a different undulating motion. There are two major classes of cilia: ''motile'' and ''non-motile'' cilia, each with a subtype, giving four types in all. A cell will typically have one primary cilium or many motile cilia. The structure of the cilium core called the axoneme determines the cilium class. Most motile cilia have a central pair of single microtubules surrounded by nine pairs of double microtubules called a 9+2 axoneme. Most non-motile cilia have a 9+0 axoneme that lacks the central pair of mi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
