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Hematophagy
Hematophagy (sometimes spelled haematophagy or hematophagia) is the practice by certain animals of feeding on blood (from the Greek words αἷμα ' "blood" and φαγεῖν ' "to eat"). Since blood is a fluid tissue rich in nutritious proteins and lipids that can be taken without great effort, hematophagy is a preferred form of feeding for many small animals, such as worms and arthropods. Some intestinal nematodes, such as Ancylostomatids, feed on blood extracted from the capillaries of the gut, and about 75 percent of all species of leeches (e.g., ''Hirudo medicinalis'') are hematophagous. The spider Evarcha culicivora feeds indirectly on vertebrate blood by specializing on blood-filled female mosquitoes as their preferred prey. Some fish, such as lampreys and candirus, and mammals, especially the vampire bats, and birds, such as the vampire finches, hood mockingbirds, the Tristan thrush, and oxpeckers also practise hematophagy. Mechanism and evolution These hematophag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vampire Bat
Vampire bats, species of the subfamily Desmodontinae, are leaf-nosed bats found in Central and South America. Their food source is blood of other animals, a dietary trait called hematophagy. Three extant bat species feed solely on blood: the common vampire bat (''Desmodus rotundus''), the hairy-legged vampire bat (''Diphylla ecaudata''), and the white-winged vampire bat (''Diaemus youngi''). All three species are native to the Americas, ranging from Mexico to Brazil, Chile, Uruguay and Argentina. Taxonomy Due to differences among the three species, each has been placed within a different genus, each consisting of one extant species. In the older literature, these three genera were placed within a family of their own, Desmodontidae, but taxonomists have now grouped them as a subfamily, Desmodontinae, in the New World leaf-nosed bat family, Phyllostomidae. The three known species of vampire bats all seem more similar to one another than to any other species. That suggests that he ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vampire Finch
The vampire ground finch (''Geospiza septentrionalis'') is a small bird native to the Galápagos Islands. It was considered a very distinct subspecies of the sharp-beaked ground finch (''Geospiza difficilis'') endemic to Wolf and Darwin Islands.Grant, Peter R.; Grant, B. Rosemary & Petren, Kenneth (2000). The allopatric phase of speciation: the sharp-beaked ground finch (''Geospiza difficilis'') on the Galápagos islands. '' Biol. J. Linn. Soc.'' 69(3): 287–317. The International Ornithologists' Union has split the species supported by strong genetic evidence that they are not closely related, and divergences in morphology and song. Other taxonomic authorities still consider it conspecific. Description The vampire finch is sexually dimorphic as typical for its genus, with the males being primarily black and the females grey with brown streaks. It has a lilting song on Wolf, a buzzing song on Darwin, and whistling calls on both islands; only on Wolf, a drawn-out, buzzing call i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anopheles Stephensi
''Anopheles stephensi'' is a primary mosquito vector of malaria in urban India and is included in the same subgenus as ''Anopheles gambiae'', the primary malaria vector in Africa. ''A. gambiae'' consists of a complex of morphologically identical species of mosquitoes, along with all other major malaria vectors; however, ''A. stephensi'' has not yet been included in any of these complexes. Nevertheless, two races of ''A. stephensi'' exist based on differences in egg dimensions and the number of ridges on the eggs; ''A. s. stephensi'' ''sensu stricto'', the type form, is a competent malaria vector that takes place in urban areas, and ''A. s. mysorensis'', the variety form, exists in rural areas and exhibits considerable zoophilic behaviour, making it a poor malaria vector. However, ''A. s. mysorensis'' is a detrimental vector in Iran.Sinka, M.E., Bangs, M.J., Manguin, S., Chareonviriyaphap, T., Patil, A.P., Temperley, W.H., Gething, P. W., Elyazar, I.R.F., Kabaria, C.W., Harbach, R. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lamprey
Lampreys (sometimes inaccurately called lamprey eels) are an ancient extant lineage of jawless fish of the order Petromyzontiformes , placed in the superclass Cyclostomata. The adult lamprey may be characterized by a toothed, funnel-like sucking mouth. The common name "lamprey" is probably derived from Latin , which may mean "stone licker" ( "to lick" + "stone"), though the etymology is uncertain. ''Lamprey'' is sometimes seen for the plural form. There are about 38 known extant species of lampreys and five known extinct species. Parasitic carnivorous species are the most well-known, and feed by boring into the flesh of other fish to suck their blood; but only 18 species of lampreys engage in this micropredatory lifestyle. Of the 18 carnivorous species, nine migrate from saltwater to freshwater to breed (some of them also have freshwater populations), and nine live exclusively in freshwater. All non-carnivorous forms are freshwater species. Adults of the non-carnivorous ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemostasis
In biology, hemostasis or haemostasis is a process to prevent and stop bleeding, meaning to keep blood within a damaged blood vessel (the opposite of hemostasis is hemorrhage). It is the first stage of wound healing. This involves coagulation, which changes blood from a liquid to a gel. Intact blood vessels are central to moderating blood's tendency to form clots. The endothelial cells of intact vessels prevent blood clotting with a heparin-like molecule and thrombomodulin, and prevent platelet aggregation with nitric oxide and prostacyclin. When endothelium of a blood vessel is damaged, the endothelial cells stop secretion of coagulation and aggregation inhibitors and instead secrete von Willebrand factor, which initiate the maintenance of hemostasis after injury. Hemostasis involves three major steps: * vasoconstriction * temporary blockage of a hole in a damaged blood vessel by a platelet plug * blood coagulation (formation of fibrin clots) These processes seal the injury or ho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Incisor
Incisors (from Latin ''incidere'', "to cut") are the front teeth present in most mammals. They are located in the premaxilla above and on the mandible below. Humans have a total of eight (two on each side, top and bottom). Opossums have 18, whereas armadillos have none. Structure Adult humans normally have eight incisors, two of each type. The types of incisor are: * maxillary central incisor (upper jaw, closest to the center of the lips) * maxillary lateral incisor (upper jaw, beside the maxillary central incisor) * mandibular central incisor (lower jaw, closest to the center of the lips) * mandibular lateral incisor (lower jaw, beside the mandibular central incisor) Children with a full set of deciduous teeth (primary teeth) also have eight incisors, named the same way as in permanent teeth. Young children may have from zero to eight incisors depending on the stage of their tooth eruption and tooth development. Typically, the mandibular central incisors erupt first, followed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capillary
A capillary is a small blood vessel from 5 to 10 micrometres (μm) in diameter. Capillaries are composed of only the tunica intima, consisting of a thin wall of simple squamous endothelial cells. They are the smallest blood vessels in the body: they convey blood between the arterioles and venules. These microvessels are the site of exchange of many substances with the interstitial fluid surrounding them. Substances which cross capillaries include water, oxygen, carbon dioxide, urea, glucose, uric acid, lactic acid and creatinine. Lymph capillaries connect with larger lymph vessels to drain lymphatic fluid collected in the microcirculation. During early embryonic development, new capillaries are formed through vasculogenesis, the process of blood vessel formation that occurs through a '' de novo'' production of endothelial cells that then form vascular tubes. The term '' angiogenesis'' denotes the formation of new capillaries from pre-existing blood vessels and already present ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proboscis
A proboscis () is an elongated appendage from the head of an animal, either a vertebrate or an invertebrate. In invertebrates, the term usually refers to tubular mouthparts used for feeding and sucking. In vertebrates, a proboscis is an elongated nose or snout. Etymology First attested in English in 1609 from Latin , the latinisation of the Ancient Greek (), which comes from () 'forth, forward, before' + (), 'to feed, to nourish'. The plural as derived from the Greek is , but in English the plural form ''proboscises'' occurs frequently. Invertebrates The most common usage is to refer to the tubular feeding and sucking organ of certain invertebrates such as insects (e.g., moths, butterflies, and mosquitoes), worms (including Acanthocephala, proboscis worms) and gastropod molluscs. Acanthocephala The Acanthocephala or thorny-headed worms, or spiny-headed worms are characterized by the presence of an eversible proboscis, armed with spines, which it uses to pierce and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Host (biology)
In biology and medicine, a host is a larger organism that harbours a smaller organism; whether a parasite, parasitic, a mutualism (biology), mutualistic, or a commensalism, commensalist ''guest'' (symbiont). The guest is typically provided with nourishment and shelter. Examples include animals playing host to parasitic worms (e.g. nematodes), cell (biology), cells harbouring pathogenic (disease-causing) viruses, a Fabaceae, bean plant hosting mutualistic (helpful) Rhizobia, nitrogen-fixing bacteria. More specifically in botany, a host plant supplies nutrient, food resources to micropredators, which have an evolutionarily stable strategy, evolutionarily stable relationship with their hosts similar to ectoparasitism. The host range is the collection of hosts that an organism can use as a partner. Symbiosis Symbiosis spans a wide variety of possible relationships between organisms, differing in their permanence and their effects on the two parties. If one of the partners in an ass ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mouth
In animal anatomy, the mouth, also known as the oral cavity, or in Latin cavum oris, is the opening through which many animals take in food and issue vocal sounds. It is also the cavity lying at the upper end of the alimentary canal, bounded on the outside by the lips and inside by the pharynx. In tetrapods, it contains the tongue and, except for some like birds, teeth. This cavity is also known as the buccal cavity, from the Latin ''bucca'' ("cheek"). Some animal phyla, including arthropods, molluscs and chordates, have a complete digestive system, with a mouth at one end and an anus at the other. Which end forms first in ontogeny is a criterion used to classify bilaterian animals into protostomes and deuterostomes. Development In the first multicellular animals, there was probably no mouth or gut and food particles were engulfed by the cells on the exterior surface by a process known as endocytosis. The particles became enclosed in vacuoles into which enzymes were secr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxpeckers
The oxpeckers are two species of bird which make up the genus ''Buphagus'', and family Buphagidae. The oxpeckers were formerly usually treated as a subfamily, Buphaginae, within the starling family, Sturnidae, but molecular phylogenetic studies have consistently shown that they form a separate lineage that is basal to the sister clades containing the Sturnidae and the Mimidae (mockingbirds, thrashers, and allies). Oxpeckers are endemic to the savanna of Sub-Saharan Africa. Both the English and scientific names arise from their habit of perching on large mammals (both wild and domesticated) such as cattle, zebras, impalas, hippopotamuses, rhinoceroses, and giraffes, eating ticks, small insects, botfly larvae, and other parasites, as well as the animals' blood. The behaviour of oxpeckers towards large mammals was thought to be exclusively mutual, though recent research suggests the relationship can be parasitic in nature as well. The swahili name for the red-billed oxpecke ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tristan Thrush
The Tristan thrush (''Turdus eremita''), also known as the starchy,Hince (2000). is a species of bird in the thrush family that is endemic to the British overseas territories of the isolated Tristan da Cunha archipelago in the South Atlantic Ocean. Description The bird was described by John Gould as being similar in size and appearance to the song thrush, and by Henry Moseley as like a very dark-coloured song thrush. However, it also has the short rounded wings and reduced keel indicative of a reduced need for flight, typical of bird species adapted to life on small islands. This thrush typically has a length of about . The nominate subspecies from Tristan differs from that from Nightingale Island, with the Tristan birds being warm dark brown on the upperparts rather than dull sooty-brown, rufous rather than dark fuscous on the sides of the head, and rufous-brown, rather than brownish-black, on the underparts. Birds from Inaccessible Island appear to be intermediate, with the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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