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Macrohectopus Branickii
''Macrohectopus branickii'' is a species of amphipod (a group containing the scuds) living in the pelagic zone of Lake Baikal, believed to be the only species of amphipod in this niche within freshwater (many more amphipods are pelagic/planktonic in the sea, such as the Hyperiids). It is the only known species within the genus ''Macrohectopus'' and the only member of the family Macrohectopidae. The sheer scale of Lake Baikal allows many species, including ''M. branickii'', to occupy such niches which do not exist in other freshwater ecosystem Freshwater ecosystems are a subset of Earth's aquatic ecosystems that include the biological communities inhabiting freshwater waterbodies such as lakes, ponds, rivers, streams, springs, bogs, and wetlands. They can be contrasted with marine ec ...s. These pelagic amphipods are prey to many animals within its ecosystem, including the top predator, top aquatic predator of the lake, the Baikal seal. Description ''Macrohectopus brani ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stebbing (taxonomy)
The Reverend Thomas Roscoe Rede Stebbing (6 February 1835, London – 8 July 1926, Royal Tunbridge Wells) was a British zoology, zoologist, who described himself as "a serf to natural history, principally employed about crustacean, Crustacea". Educated in London and Oxford, he only took to natural history in his thirties, having worked as a teacher until then. Although an ordained Anglican priest, Stebbing promoted Darwinism in a number of popular works, and was banned from preaching as a result. His scientific works mostly concerned crustaceans, especially the Amphipoda and Isopoda, the most notable being his work on the amphipods of the Challenger expedition, ''Challenger'' expedition. His zoological author abbreviation is Stebbing. Biography Thomas Roscoe Rede Stebbing was born on 6 February 1835 in Euston Square, London, the seventh of thirteen or fourteen children, to a clergyman and the editor of the ''Athenaeum (British magazine), Athenaeum'', Henry Stebbing (editor), H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species Description
A species description is a formal scientific description of a newly encountered species, typically articulated through a scientific publication. Its purpose is to provide a clear description of a new species of organism and explain how it differs from species that have been previously described or related species. For a species to be considered valid, a species description must follow established guidelines and naming conventions dictated by relevant nomenclature codes. These include the International Code of Zoological Nomenclature (ICZN) for animals, the International Code of Nomenclature for algae, fungi, and plants (ICN) for plants, and the International Committee on Taxonomy of Viruses (ICTV) for viruses. A species description often includes photographs or other illustrations of type material and information regarding where this material is deposited. The publication in which the species is described gives the new species a formal scientific name. Some 1.9 million ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Camouflage
Camouflage is the use of any combination of materials, coloration, or illumination for concealment, either by making animals or objects hard to see, or by disguising them as something else. Examples include the leopard's spotted coat, the battledress of a modern soldier, and the leaf-mimic katydid's wings. A third approach, motion dazzle, confuses the observer with a conspicuous pattern, making the object visible but momentarily harder to locate. The majority of camouflage methods aim for crypsis, often through a general resemblance to the background, high contrast disruptive coloration, eliminating shadow, and countershading. In the open ocean, where there is no background, the principal methods of camouflage are transparency, silvering, and countershading, while the bioluminescence, ability to produce light is among other things used for counter-illumination on the undersides of cephalopods such as squid. Some animals, such as chameleons and octopuses, are capable of Active ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dissection
Dissection (from Latin ' "to cut to pieces"; also called anatomization) is the dismembering of the body of a deceased animal or plant to study its anatomical structure. Autopsy is used in pathology and forensic medicine to determine the cause of death in humans. Less extensive dissection of plants and smaller animals preserved in a formaldehyde solution is typically carried out or demonstrated in biology and natural science classes in middle school and high school, while extensive dissections of cadavers of adults and children, both fresh and preserved are carried out by medical students in medical schools as a part of the teaching in subjects such as anatomy, pathology and forensic medicine. Consequently, dissection is typically conducted in a morgue or in an anatomy lab. Dissection has been used for centuries to explore anatomy. Objections to the use of cadavers have led to the use of alternatives including virtual dissection of computational anatomy, computer models. In the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Muscle Fiber
A muscle cell, also known as a myocyte, is a mature contractile cell in the muscle of an animal. In humans and other vertebrates there are three types: skeletal, smooth, and cardiac (cardiomyocytes). A skeletal muscle cell is long and threadlike with many nuclei and is called a ''muscle fiber''. Muscle cells develop from embryonic precursor cells called myoblasts. Skeletal muscle cells form by fusion of myoblasts to produce multinucleated cells (syncytia) in a process known as myogenesis. Skeletal muscle cells and cardiac muscle cells both contain myofibrils and sarcomeres and form a striated muscle tissue. Cardiac muscle cells form the cardiac muscle in the walls of the heart chambers, and have a single central nucleus. Cardiac muscle cells are joined to neighboring cells by intercalated discs, and when joined in a visible unit they are described as a ''cardiac muscle fiber''. Smooth muscle cells control involuntary movements such as the peristalsis contractions in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transparency And Translucency
In the field of optics, transparency (also called pellucidity or diaphaneity) is the physical property of allowing light to pass through the material without appreciable scattering of light. On a macroscopic scale (one in which the dimensions are much larger than the wavelengths of the photons in question), the photons can be said to follow Snell's law. Translucency (also called translucence or translucidity) is the physical property of allowing light to pass through the material (with or without scattering of light). It allows light to pass through but the light does not necessarily follow Snell's law on the macroscopic scale; the photons may be scattered at either of the two interfaces, or internally, where there is a change in the index of refraction. In other words, a translucent material is made up of components with different indices of refraction. A transparent material is made up of components with a uniform index of refraction. Transparent materials appear clear, with t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chitin
Chitin (carbon, C8hydrogen, H13oxygen, O5nitrogen, N)n ( ) is a long-chain polymer of N-Acetylglucosamine, ''N''-acetylglucosamine, an amide derivative of glucose. Chitin is the second most abundant polysaccharide in nature (behind only cellulose); an estimated 1 billion tons of chitin are produced each year in the biosphere. It is a primary component of cell walls in fungi (especially filamentous and mushroom-forming fungi), the exoskeletons of arthropods such as crustaceans and insects, the radulae, cephalopod beaks and Gladius (cephalopod), gladii of molluscs and in some nematodes and diatoms. It is also synthesised by at least some fish and lissamphibians. Commercially, chitin is extracted from the shells of crabs, shrimps, shellfish and lobsters, which are major by-products of the seafood industry. The structure of chitin is comparable to cellulose, forming crystalline nanofibrils or whiskers. It is functionally comparable to the protein keratin. Chitin has proved useful ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brood Pouch (Peracarida)
The marsupium or brood pouch, is a characteristic feature of Peracarida, including the orders Amphipoda, Isopoda, and Cumacea Cumacea is an order (biology), order of small marine crustaceans of the superorder Peracarida, occasionally called hooded shrimp or comma shrimp. Their unique appearance and uniform body plan makes them easy to distinguish from other crustaceans. .... It is an egg chamber formed by oostegites, which are appendages that are attached to the coxae (first segment) of the first pereiopods. Females lay their eggs directly into the brood chamber, and the young will develop there, undergoing several moults before emerging as miniature adults referred to as mancae. Males have no marsupium. References {{malacostraca-stub Crustacean anatomy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gill
A gill () is a respiration organ, respiratory organ that many aquatic ecosystem, aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they are kept moist. The microscopic structure of a gill presents a large surface area to the external environment. Branchia (: branchiae) is the zoologists' name for gills (from Ancient Greek ). With the exception of some aquatic insects, the filaments and lamella (surface anatomy), lamellae (folds) contain blood or Coelom#Coelomic fluid, coelomic fluid, from which gases are exchanged through the thin walls. The blood carries oxygen to other parts of the body. Carbon dioxide passes from the blood through the thin gill tissue into the water. Gills or gill-like organs, located in different parts of the body, are found in various groups of aquatic animals, including Mollusc, molluscs, crustaceans, insects, fish, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tergum
A ''tergum'' (Latin for "the back"; : ''terga'', associated adjective tergal) is the dorsal ('upper') portion of an arthropod Arthropods ( ) are invertebrates in the phylum Arthropoda. They possess an arthropod exoskeleton, exoskeleton with a cuticle made of chitin, often Mineralization (biology), mineralised with calcium carbonate, a body with differentiated (Metam ... segment other than the head. The anterior edge is called the 'base' and posterior edge is called the 'apex' or 'margin'. A given tergum may be divided into hardened plates or sclerites commonly referred to as tergites. In a thoracic segment, for example, the tergum may be divided into an anterior notum and a posterior scutellum. Lateral extensions of a tergite are known as paranota (Greek for "alongside the back") or ''carinae'' (Latin for "keel"), exemplified by the flat-backed millipedes of the order Polydesmida. Kinorhynchs have tergal and sternal plates too, though seemingly not homologous with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compound Eye
A compound eye is a Eye, visual organ found in arthropods such as insects and crustaceans. It may consist of thousands of ommatidium, ommatidia, which are tiny independent photoreception units that consist of a cornea, lens (anatomy), lens, and photoreceptor cells which distinguish brightness and color. The image perceived by this arthropod eye is a combination of inputs from the numerous ommatidia, which are oriented to point in slightly different directions. Compared with single-aperture eyes, compound eyes have poor image resolution; however, they possess a very large view angle and the ability to detect fast movement and, in some cases, the Polarization (waves), polarization of light. Because a compound eye is made up of a collection of ommatidia, each with its own lens, light will enter each ommatidium instead of using a single entrance point. The individual light receptors behind each lens are then turned on and off due to a series of changes in the light intensity during mov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
