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Dasyatis Acutirostra
:''"Sharpnose stingray" may also refer to '' Dasyatis zugei'', ''Himantura gerrardi'', or '' Himantura jenkinsii. The sharpnose stingray (''Telatrygon acutirostra'') is a little-known species of stingray in the family Dasyatidae, found off southern Japan and in the East China Sea. With a rounded pectoral fin disc and a long, projecting snout, ''T. acutirostra'' resembles (and was historically confused with) the smaller pale-edged stingray (''D. zugei''). A number of characteristics differentiate this species from ''D. zugei'', including larger eyes and the absence of a dorsal fin fold on the tail. The International Union for Conservation of Nature (IUCN) has assessed this species as Near Threatened, as its restricted distribution renders it vulnerable to increases in fishing pressure. Taxonomy Prior to being scientifically described, ''T. acutirostra'' has been confused for ''D. zugei''; the two species have been confounded by various authors since at least Jordan and Fowler's 19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dasyatis Zugei
The pale-edged stingray or sharpnose stingray (''Dasyatis zugei'') is a species of stingray in the family Dasyatidae, found in the Indian and Pacific Oceans from India to the western Malay Archipelago and southern Japan. This bottom-dwelling ray is most commonly found over sandy areas shallower than , as well as in estuaries. Measuring up to across, the pale-edged stingray has a diamond-shaped pectoral fin disc, a long projecting snout, small eyes, and a whip-like tail with both dorsal and ventral fin folds. It is chocolate brown above and white below. The diet of the pale-edged stingray consists mainly of small crustaceans and fishes. Reproduction is aplacental viviparous, with females bearing litters of 1–3 young. Caught as bycatch and utilized for its meat, this species is threatened by heavy fishing pressure throughout its range and has been assessed as Vulnerable by the International Union for Conservation of Nature (IUCN). Taxonomy and phylogeny German b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Specific Name (zoology)
In zoological nomenclature, the specific name (also specific epithet or species epithet) is the second part (the second name) within the scientific name of a species (a binomen). The first part of the name of a species is the name of the genus or the generic name. The rules and regulations governing the giving of a new species name are explained in the article species description. For example, the scientific name for humans is ''Homo sapiens'', which is the species name, consisting of two names: ''Homo'' is the " generic name" (the name of the genus) and ''sapiens'' is the "specific name". Historically, ''specific name'' referred to the combination of what are now called the generic and specific names. Carl Linnaeus, who formalized binomial nomenclature, made explicit distinctions between specific, generic, and trivial names. The generic name was that of the genus, the first in the binomial, the trivial name was the second name in the binomial, and the specific the proper term fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meristic
Meristics is an area of ichthyology and herpetology which relates to counting quantitative features of fish and reptiles, such as the number of fins or scales. A meristic (countable trait) can be used to describe a particular species of fish, or used to identify an unknown species. Meristic traits are often described in a shorthand notation called a ''meristic formula''. Meristic characters are the countable structures occurring in series (e.g. myomeres, vertebrae, fin rays) in fish. These characters are among the characters most commonly used for differentiation of species and populations. In the salmonids, scale counts have been most widely used for the differentiation of populations within species. In rainbow and steelhead trout the most notable differences among populations occur in counts of scales. Meristic characters are used in many other fields, such as in botany or in zoology. Meristic comparison is used in phenetic and cladistic analysis. Meristic analysis A meristic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eyeball
Eyes are organs of the visual system. They provide living organisms with vision, the ability to receive and process visual detail, as well as enabling several photo response functions that are independent of vision. Eyes detect light and convert it into electro-chemical impulses in neurons (neurones). In higher organisms, the eye is a complex optical system which collects light from the surrounding environment, regulates its intensity through a diaphragm, focuses it through an adjustable assembly of lenses to form an image, converts this image into a set of electrical signals, and transmits these signals to the brain through complex neural pathways that connect the eye via the optic nerve to the visual cortex and other areas of the brain. Eyes with resolving power have come in ten fundamentally different forms, and 96% of animal species possess a complex optical system. Image-resolving eyes are present in molluscs, chordates and arthropods. The most simple eyes, pit eyes, are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dermal Denticle
A fish scale is a small rigid plate that grows out of the skin of a fish. The skin of most jawed fishes is covered with these protective scales, which can also provide effective camouflage through the use of reflection and colouration, as well as possible hydrodynamic advantages. The term ''scale'' derives from the Old French , meaning a shell pod or husk. Scales vary enormously in size, shape, structure, and extent, ranging from strong and rigid armour plates in fishes such as shrimpfishes and boxfishes, to microscopic or absent in fishes such as eels and anglerfishes. The morphology of a scale can be used to identify the species of fish it came from. Scales originated within the jawless ostracoderms, ancestors to all jawed fishes today. Most bony fishes are covered with the cycloid scales of salmon and carp, or the ctenoid scales of perch, or the ganoid scales of sturgeons and gars. Cartilaginous fishes (sharks and rays) are covered with placoid scales. Some spec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pelvic Fin
Pelvic fins or ventral fins are paired fins located on the ventral surface of fish. The paired pelvic fins are homologous to the hindlimbs of tetrapods. Structure and function Structure In actinopterygians, the pelvic fin consists of two endochondrally-derived bony girdles attached to bony radials. Dermal fin rays ( lepidotrichia) are positioned distally from the radials. There are three pairs of muscles each on the dorsal and ventral side of the pelvic fin girdle that abduct and adduct the fin from the body. Pelvic fin structures can be extremely specialized in actinopterygians. Gobiids and lumpsuckers modify their pelvic fins into a sucker disk that allow them to adhere to the substrate or climb structures, such as waterfalls. In priapiumfish, males have modified their pelvic structures into a spiny copulatory device that grasps the female during mating. File:Pelvic fin skeleton.png, Pelvic fin skeleton for ''Danio rerio'', zebrafish. File:Zuignap waarmee de zwartbek ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quincunx
A quincunx () is a geometric pattern consisting of five points arranged in a cross, with four of them forming a square or rectangle and a fifth at its center. The same pattern has other names, including "in saltire" or "in cross" in heraldry (depending on the orientation of the outer square), the five-point stencil in numerical analysis, and the five dots tattoo. It forms the arrangement of five units in the pattern corresponding to the five-spot on six-sided dice, playing cards, and dominoes. It is represented in Unicode as or (for the die pattern) . Historical origins of the name The quincunx was originally a coin issued by the Roman Republic c. 211–200 BC, whose value was five twelfths (''quinque'' and ''uncia'') of an as, the Roman standard bronze coin. On the Roman quincunx coins, the value was sometimes indicated by a pattern of five dots or pellets. However, these dots were not always arranged in a quincunx pattern. The ''Oxford English Dictionary'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Papilla (fish Mouth Structure)
The papilla, in certain kinds of fish, particularly rays, sharks, and catfish, are small lumps of dermal tissue found in the mouth, where they are "distributed uniformly on the tongue, palate, and pharynx".B. G. Kapoor, H. E. Evans, E. A. Pevzner "The gustatory system in fish" in ''Advances in Marine Biology, Volume 13'' (1976), F. S. Russell, Maurice Yonge (eds). They "project slightly above the surrounding multi-layered epithelium", and the taste buds of the fish are "situated along the crest or at the apex of the papillae". Unlike humans, fish have little or nothing in the way of a tongue The tongue is a muscular organ in the mouth of a typical tetrapod. It manipulates food for mastication and swallowing as part of the digestive process, and is the primary organ of taste. The tongue's upper surface (dorsum) is covered by taste bu ..., and those that have such an organ do not use it for tasting, but merely for cushioning the mouth and manipulating things within it. The papill ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spiracle (vertebrates)
Spiracles () are openings on the surface of some animals, which usually lead to respiratory systems. The spiracle is a small hole behind each eye that opens to the mouth in some fish. In the jawless fish, the first gill opening immediately behind the mouth is essentially similar to the other gill opening. With the evolution of the jaw in the early jawed vertebrates, this gill slit was caught between the forward gill-rod (now functioning as the jaw) and the next rod, the hyomandibular bone, supporting the jaw hinge and anchoring the jaw to the skull proper. The gill opening was closed off from below, the remaining opening was small and hole-like, and is termed a spiracle. In many species of sharks and all rays the spiracle is responsible for the intake of water into the buccal space before being expelled from the gills. The spiracle is often located towards the top of the animal allowing breathing even while the animal is mostly buried under sediments. As sharks adapted a fast ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benthic
The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from ancient Greek, βένθος (bénthos), meaning "the depths." Organisms living in this zone are called benthos and include microorganisms (e.g., bacteria and fungi) as well as larger invertebrates, such as crustaceans and polychaetes. Organisms here generally live in close relationship with the substrate and many are permanently attached to the bottom. The benthic boundary layer, which includes the bottom layer of water and the uppermost layer of sediment directly influenced by the overlying water, is an integral part of the benthic zone, as it greatly influences the biological activity that takes place there. Examples of contact soil layers include sand bottoms, rocky outcrops, coral, and bay mud. Description Oceans The benthic region of the ocean begins at the shore line (intertida ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecuador
Ecuador ( ; ; Quechuan languages, Quechua: ''Ikwayur''; Shuar language, Shuar: ''Ecuador'' or ''Ekuatur''), officially the Republic of Ecuador ( es, República del Ecuador, which literally translates as "Republic of the Equator"; Quechuan languages, Quechua: ''Ikwadur Ripuwlika''; Shuar language, Shuar: ''Ekuatur Nunka''), is a country in northwestern South America, bordered by Colombia on the north, Peru on the east and south, and the Pacific Ocean on the west. Ecuador also includes the Galápagos Islands in the Pacific, about west of the mainland. The country's Capital city, capital and largest city is Quito. The territories of modern-day Ecuador were once home to a variety of Indigenous peoples in Ecuador, Indigenous groups that were gradually incorporated into the Inca Empire during the 15th century. The territory was Spanish colonization of the Americas, colonized by Spain during the 16th century, achieving independence in 1820 as part of Gran Colombia, from which it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
