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Sander (fish)
''Sander'' (formerly known as ''Stizostedion'') is a genus of predatory ray-finned fish in the family Percidae, which also includes the perches, ruffes, and darters. They are also known as "pike-perch" because of their resemblance to fish in the unrelated Esocidae (pike) family. They are the only genus in the monotypic tribe Luciopercini, which is one of two tribes in the subfamily Luciopercinae, Characteristics ''Sander'' species have elongated and laterally compressed bodies and they range in total length from in the Volga pikeperch (''S. volgensis'') to in the zander (''S. lucioperca''). The species within the genus share canine-like teeth that are at their largest in the zander, and although they are not present in adult Volga pikeperches, they do possess them as juveniles. in addition, they have thin rows of teeth on their jaws, vomer, and palatines, the preopercle shows strong serrations along its edges, a continuous lateral line reaches all the way from the head to t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Walleye
The walleye (''Sander vitreus'', synonym ''Stizostedion vitreum''), also called the yellow pike or yellow pickerel, is a freshwater perciform fish native to most of Canada and to the Northern United States. It is a North American close relative of the European zander, also known as the pikeperch. The walleye is sometimes called the yellow walleye to distinguish it from the blue walleye, which is a color morph that was once found in the southern Ontario and Quebec regions, but is now presumed extinct. However, recent genetic analysis of a preserved (frozen) 'blue walleye' sample suggests that the blue and yellow walleye were simply phenotypes within the same species and do not merit separate taxonomic classification. In parts of its range in English-speaking Canada, the walleye is known as a pickerel, though the fish is not related to the true pickerels, which are members of the family '' Esocidae''. Walleyes show a fair amount of variation across watersheds. In general, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monotypy
In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispecific" or "monospecific" is sometimes preferred. In botanical nomenclature, a monotypic genus is a genus in the special case where a genus and a single species are simultaneously described. In contrast, an oligotypic taxon contains more than one but only a very few subordinate taxa. Examples Just as the term ''monotypic'' is used to describe a taxon including only one subdivision, the contained taxon can also be referred to as monotypic within the higher-level taxon, e.g. a genus monotypic within a family. Some examples of monotypic groups are: Plants * In the order Amborellales, there is only one family, Amborellaceae and there is only one genus, '' Amborella'', and in this genus there is only one species, namely ''Amborella trichopoda ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edward Griffith (zoologist)
Edward Griffith (1790–1858) was a British naturalist and solicitor. He wrote ''General and Particular Descriptions of the Vertebrated Animals'' (1821) and translated Georges Cuvier's ''Règne animal'', making considerable additions (1827–35). Life The son of William Griffith of Stanwell, Middlesex, he entered St. Paul's School, London in 1800 and left it in 1806, entering the Common Pleas office as a clerk. He afterwards became a solicitor and a master in the Court of Common Pleas. He was one of the original members of the Zoological Society, and a fellow of the Linnean (1822), Antiquaries, and Royal Societies. Griffith died on 8 January 1858. Works In 1821 he published the first part of what was intended to be an extensive work, ‘General and Particular Descriptions of the Vertebrated Animals,’ with coloured plates. This first part dealt only with monkeys and lemurs. Incomplete, it may have been abandoned in favour of his translation of Cuvier's ‘Animal Kin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sander Canadensis
The sauger (''Sander canadensis'') is a freshwater perciform fish of the family Percidae that resembles its close relative, the walleye. The species is a member of the largest vertebrate order, the Perciformes.Jaeger, Matthew. 2004. Montana's Fish Species of Special Concern: Sauger. Montana Cooperative Fisheries Research Unit. http://www.fisheriessociety.org/AFSmontana/SSCpages/Sauger%20Status.htm. (Accessed May 2011). It is the most migratory percid species in North America.Kuhn et al. 2008. Habitat Use and Movement Patterns by Adult Saugers from fall to Summer in an Unimpounded Small-River System. ''North American Journal of Fisheries Management''. 28: 360-367. American Fisheries Society. 2008. Saugers have two dorsal fins; the first is spiny and the posterior dorsal fin is soft-rayed. Their paired fins are in the thoracic position and their caudal fin is truncated, which means squared off at the corners, a characteristic of the family Percidae. Another physical characteristic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piscivory
A piscivore () is a carnivorous animal that eats primarily fish. The name ''piscivore'' is derived . Piscivore is equivalent to the Greek-derived word ichthyophage, both of which mean "fish eater". Fish were the diet of early tetrapod evolution (via water-bound amphibians during the Devonian period); insectivory came next; then in time, the more terrestrially adapted reptiles and synapsids evolved herbivory. Almost all predatory fishes (most sharks, tuna, billfishes, pikes etc.) are obligated piscivores. Some non-piscine aquatic animals, such as whales, sea lion and crocodilians, are not completely piscivorous, often also preying on invertebrates, marine mammals, waterbirds and even wading land animals in addition to fish; while others, such as the bulldog bat and gharial, are strictly dependent on fish for food. Some creatures, including cnidarians, octopuses, squid, spiders, cetaceans, grizzly bears, jaguars, wolves, snakes, turtles and sea gulls, may have fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tapetum Lucidum
The ''tapetum lucidum'' ( ; ; ) is a layer of tissue in the eye of many vertebrates and some other animals. Lying immediately behind the retina, it is a retroreflector. It reflects visible light back through the retina, increasing the light available to the photoreceptors (although slightly blurring the image). The tapetum lucidum contributes to the superior night vision of some animals. Many of these animals are nocturnal, especially carnivores, while others are deep sea animals. Similar adaptations occur in some species of spiders. Haplorhine primates, including humans, are diurnal and lack a ''tapetum lucidum''. Function and mechanism Presence of a ''tapetum lucidum'' enables animals to see in dimmer light than would otherwise be possible. The ''tapetum lucidum'', which is iridescent, reflects light roughly on the interference principles of thin-film optics, as seen in other iridescent tissues. However, the ''tapetum lucidum'' cells are leucophores, not iridophores ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retina
The retina (from la, rete "net") is the innermost, light-sensitive layer of tissue of the eye of most vertebrates and some molluscs. The optics of the eye create a focused two-dimensional image of the visual world on the retina, which then processes that image within the retina and sends nerve impulses along the optic nerve to the visual cortex to create visual perception. The retina serves a function which is in many ways analogous to that of the film or image sensor in a camera. The neural retina consists of several layers of neurons interconnected by synapses and is supported by an outer layer of pigmented epithelial cells. The primary light-sensing cells in the retina are the photoreceptor cells, which are of two types: rods and cones. Rods function mainly in dim light and provide monochromatic vision. Cones function in well-lit conditions and are responsible for the perception of colour through the use of a range of opsins, as well as high-acuity vision used fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anal Fin
Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as seen in sharks. Apart from the tail or caudal fin, fish fins have no direct connection with the spine and are supported only by muscles. Their principal function is to help the fish swim. Fins located in different places on the fish serve different purposes such as moving forward, turning, keeping an upright position or stopping. Most fish use fins when swimming, flying fish use pectoral fins for gliding, and frogfish use them for crawling. Fins can also be used for other purposes; male sharks and mosquitofish use a modified fin to deliver sperm, thresher sharks use their caudal fin to stun prey, reef stonefish have spines in their dorsal fins that inject venom, anglerfish use the first spine of their dorsal fin like a fishing rod to lu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glossary Of Ichthyology
This glossary of ichthyology is a list of definitions of terms and concepts used in ichthyology, the study of fishes. A B C D E F G H I J K L M N O P R S T U V W {{glossaryend * Fishkeeping Ichthyology ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caudal Fin
Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as seen in sharks. Apart from the tail or caudal fin, fish fins have no direct connection with the spine and are supported only by muscles. Their principal function is to help the fish swim. Fins located in different places on the fish serve different purposes such as moving forward, turning, keeping an upright position or stopping. Most fish use fins when swimming, flying fish use pectoral fins for gliding, and frogfish use them for crawling. Fins can also be used for other purposes; male sharks and mosquitofish use a modified fin to deliver sperm, thresher sharks use their caudal fin to stun prey, reef stonefish have spines in their dorsal fins that inject venom, anglerfish use the first spine of their dorsal fin like a fishing rod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lateral Line
The lateral line, also called the lateral line organ (LLO), is a system of sensory organs found in fish, used to detect movement, vibration, and pressure gradients in the surrounding water. The sensory ability is achieved via modified epithelial cells, known as hair cells, which respond to displacement caused by motion and transduce these signals into electrical impulses via excitatory synapses. Lateral lines serve an important role in schooling behavior, predation, and orientation. Fish can use their lateral line system to follow the vortices produced by fleeing prey. Lateral lines are usually visible as faint lines of pores running lengthwise down each side, from the vicinity of the gill covers to the base of the tail. In some species, the receptive organs of the lateral line have been modified to function as electroreceptors, which are organs used to detect electrical impulses, and as such, these systems remain closely linked. Most amphibian larvae and some fully aquatic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish Measurement
Fish measurement is the measuring of individual fish and various parts of their anatomies. These data are used in many areas of ichthyology, including taxonomy and fisheries biology. Overall length * Standard length (SL) is the length of a fish measured from the tip of the snout to the posterior end of the last vertebra or to the posterior end of the midlateral portion of the hypural plate. Simply put, this measurement excludes the length of the caudal (tail) fin. * Total length (TL) is the length of a fish measured from the tip of the snout to the tip of the longer lobe of the caudal fin, usually measured with the lobes compressed along the midline. It is a straight-line measure, not measured over the curve of the body. Standard length measurements are used with Teleostei (most bony fish), while total length measurements are used with Myxini ( hagfish), Petromyzontiformes ( lampreys), and (usually) Elasmobranchii (shark Sharks are a group of elasmobranch fish characte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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