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Downrigger
A downrigger is a device used while fishing using the trolling method, which places a lure at the desired depth. A downrigger consists of a three to six-foot horizontal pole which supports a cannonball, generally 10 to 15 pounds, by a steel cable (generally stainless steel or wire). A clip, also known as a "release," attaches a fishing line to the cannonball weight. The bait or lure is attached to the release. Operation of a downrigger Downriggers consist of four major components, the weight, cable, pole or boom, and the spool. A fishing line is attached to the downrigger cable by means of a "line release." The weight is normally a five-to-twenty-pound mass of lead which is connected to the stainless steel cable. The spool is brought up either by a manual crank or via an electric motor. In addition to attaching a lure to the fishing line, an oval piece of metal or plastic (often hammered or curved for reflective purposes) called a dodger or flasher is often used to attract f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Troll (angling)
Trolling is a method of fishing where one or more fishing lines, baited with lures or bait fish, are drawn through the water. This may be behind a moving boat, or by slowly winding the line in when fishing from a static position, or even sweeping the line from side-to-side, e.g. when fishing from a jetty. Trolling is used to catch pelagic fish such as salmon, mackerel and kingfish. In American English, trolling can be phonetically confused with trawling, a different method of fishing where a net (trawl) is drawn through the water instead of lines. Trolling is used both for recreational and commercial fishing whereas trawling is used mainly for commercial fishing. Trolling from a moving boat involves moving quite slowly through the water. This can be accomplished with the use of a special trolling motor. Multiple lines are often used, and outriggers can be used to spread the lines more widely and reduce their chances of tangling. Downriggers can also be used to keep the lures ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cannon Downrigger
A cannon is a large-caliber gun classified as a type of artillery, which usually launches a projectile using explosive chemical propellant. Gunpowder ("black powder") was the primary propellant before the invention of smokeless powder during the late 19th century. Cannons vary in gauge, effective range, mobility, rate of fire, angle of fire and firepower; different forms of cannon combine and balance these attributes in varying degrees, depending on their intended use on the battlefield. A cannon is a type of heavy artillery weapon. The word ''cannon'' is derived from several languages, in which the original definition can usually be translated as ''tube'', ''cane'', or ''reed''. In the modern era, the term ''cannon'' has fallen into decline, replaced by ''guns'' or ''artillery'', if not a more specific term such as howitzer or mortar, except for high-caliber automatic weapons firing bigger rounds than machine guns, called autocannons. The earliest known depiction of cann ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fishfinder
A fishfinder or sounder (Australia) is an instrument used to locate fish underwater by detecting reflected pulses of sound energy, as in sonar. A modern fishfinder displays measurements of reflected sound on a graphical display, allowing an operator to interpret information to locate schools of fish, underwater debris, and the bottom of body of water. Fishfinder instruments are used both by sport and commercial fishermen. Modern electronics allows a high degree of integration between the fishfinder system, marine radar, compass and GPS navigation systems. Fathometer Fish finders were derived from ''fathometer''s, active sonar instruments used for navigation and safety to determine the depth of water. The fathom is a unit of water depth, from which the instrument gets its name. The fathometer is an echo sounding system for measurement of water depth. A fathometer will display water depth and can make an automatic permanent record of measurements. Since both fathometers and fis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rainbow Trout
The rainbow trout (''Oncorhynchus mykiss'') is a species of trout native to cold-water tributaries of the Pacific Ocean in Asia and North America. The steelhead (sometimes called "steelhead trout") is an anadromous (sea-run) form of the coastal rainbow trout or Columbia River redband trout that usually returns to freshwater to spawn after living two to three years in the ocean. Freshwater forms that have been introduced into the Great Lakes and migrate into tributaries to spawn are also called steelhead. Adult freshwater stream rainbow trout average between , while lake-dwelling and anadromous forms may reach . Coloration varies widely based on subspecies, forms, and habitat. Adult fish are distinguished by a broad reddish stripe along the lateral line, from gills to the tail, which is most vivid in breeding males. Wild-caught and hatchery-reared forms of the species have been transplanted and introduced for food or sport in at least 45 countries and every continent except ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brown Trout
The brown trout (''Salmo trutta'') is a European species of salmonid fish that has been widely introduced into suitable environments globally. It includes purely freshwater populations, referred to as the riverine ecotype, ''Salmo trutta'' morpha ''fario'', a lacustrine ecotype, ''S. trutta'' morpha ''lacustris'', also called the lake trout, and anadromous forms known as the sea trout, ''S. trutta'' morpha ''trutta''. The latter migrates to the oceans for much of its life and returns to fresh water only to spawn. Sea trout in Ireland and Britain have many regional names: sewin in Wales, finnock in Scotland, peal in the West Country, mort in North West England, and white trout in Ireland. The lacustrine morph of brown trout is most usually potamodromous, migrating from lakes into rivers or streams to spawn, although evidence indicates some stocks spawn on wind-swept shorelines of lakes. ''S. trutta'' morpha ''fario'' forms stream-resident populations, typically in alpine stre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Trout
The lake trout (''Salvelinus namaycush'') is a freshwater char living mainly in lakes in northern North America. Other names for it include mackinaw, namaycush, lake char (or charr), touladi, togue, and grey trout. In Lake Superior, it can also be variously known as siscowet, paperbelly and lean. The lake trout is prized both as a game fish and as a food fish. Those caught with dark coloration may be called ''mud hens''. Taxonomy It is the only member of the subgenus ''Cristovomer'', which is more derived than the subgenus '' Baione'' (the most basal clade of ''Salvelinus'', containing the brook trout (''S. fontinalis'') and silver trout (''S. agasizii'')) but still basal to the other members of ''Salvelinus''. Range From a zoogeographical perspective, lake trout have a relatively narrow distribution. They are native only to the northern parts of North America, principally Canada, but also Alaska and, to some extent, the northeastern United States. Lake trout have been wide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atlantic Salmon
The Atlantic salmon (''Salmo salar'') is a species of ray-finned fish in the family Salmonidae. It is the third largest of the Salmonidae, behind Siberian taimen and Pacific Chinook salmon, growing up to a meter in length. Atlantic salmon are found in the northern Atlantic Ocean and in rivers that flow into it. Most populations are anadromous, hatching in streams and rivers but moving out to sea as they grow where they mature, after which the adults seasonally move upstream again to spawn. When the mature fish re-enter rivers to spawn, they change in colour and appearance. Some populations of this fish only migrate to large lakes, and are "landlocked", spending their entire lives in freshwater. Such populations are found throughout the range of the species. Unlike Pacific species of salmon, ''S. salar'' is iteroparous, which means it can survive spawning and return to sea to repeat the process again in another year. Such individuals can grow to extremely large sizes, althoug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chinook Salmon
The Chinook salmon (''Oncorhynchus tshawytscha'') is the largest and most valuable species of Pacific salmon in North America, as well as the largest in the genus ''Oncorhynchus''. Its common name is derived from the Chinookan peoples. Other vernacular names for the species include king salmon, Quinnat salmon, Tsumen, spring salmon, chrome hog, Blackmouth, and Tyee salmon. The scientific species name is based on the Russian common name ''chavycha'' (чавыча). Chinook are anadromous fish native to the North Pacific Ocean and the river systems of western North America, ranging from California to Alaska, as well as Asian rivers ranging from northern Japan to the Palyavaam River in the Arctic northeast Siberia. They have been introduced to other parts of the world, including New Zealand, thriving in Lake Michigan Great Lakes of North America and Michigan's western rivers, and Patagonia. A large Chinook is a prized and sought-after catch for a sporting angler. The flesh of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined. The most recent rigorous estimate for the total number of species of eukaryotes is between 8 and 8.7 million. However, only about 14% of these had been described by 2011. All species (except viruses) are given a two-part name, a "binomial". The first part of a binomial is the genus to which the species belongs. The second part is called the specific name or the specific epithet (in botanical nomenclature, also sometimes i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermocline
A thermocline (also known as the thermal layer or the metalimnion in lakes) is a thin but distinct layer in a large body of fluid (e.g. water, as in an ocean or lake; or air, e.g. an atmosphere) in which temperature changes more drastically with depth than it does in the layers above or below. In the ocean, the thermocline divides the upper mixed layer from the calm deep water below. Depending largely on season, latitude, and turbulent mixing by wind, thermoclines may be a semi-permanent feature of the body of water in which they occur, or they may form temporarily in response to phenomena such as the radiative heating/cooling of surface water during the day/night. Factors that affect the depth and thickness of a thermocline include seasonal weather variations, latitude, and local environmental conditions, such as tides and currents. Oceans Most of the heat energy of the sunlight that strikes the Earth is absorbed in the first few centimeters at the ocean's surface, which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trolling
In slang, a troll is a person who posts or makes inflammatory, insincere, digressive, extraneous, or off-topic messages online (such as in social media, a newsgroup, a forum, a chat room, a online video game), or in real life, with the intent of provoking others into displaying emotional responses, or manipulating others' perception. The behavior is typically for the troll's amusement, or to achieve a specific result such as disrupting a rival's online activities or purposefully causing confusion or harm to other users online. In this context, both the noun and the verb forms of "troll" are frequently associated with Internet discourse. Media attention in recent years has equated trolling with online harassment. ''The Courier-Mail'' and ''The Today Show'' have used "troll" to mean "a person who defaces Internet tribute sites with the aim of causing grief to families". In addition, depictions of trolling have been included in popular fictional works, such as the HBO televis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shoaling And Schooling
In biology, any group of fish that stay together for social reasons are shoaling, and if the group is swimming in the same direction in a coordinated manner, they are schooling. In common usage, the terms are sometimes used rather loosely. About one quarter of fish species shoal all their lives, and about one half shoal for part of their lives. Fish derive many benefits from shoaling behaviour including defence against predators (through better predator detection and by diluting the chance of individual capture), enhanced foraging success, and higher success in finding a mate. It is also likely that fish benefit from shoal membership through increased hydrodynamic efficiency. Fish use many traits to choose shoalmates. Generally they prefer larger shoals, shoalmates of their own species, shoalmates similar in size and appearance to themselves, healthy fish, and kin (when recognized). The oddity effect posits that any shoal member that stands out in appearance will be preferen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
