Trout are

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 s ...

freshwater fish Freshwater fish are those that spend some or all of their lives in fresh water, such as rivers and lakes, with a salinity of less than 1.05%. These environments differ from marine conditions in many ways, especially the difference in levels of ...

belonging to the genera '' Oncorhynchus'', ''

Salmo ''Salmo'' is a genus of ray-finned fish from the family Salmonidae. The single ''Salmo'' species naturally found in the Atlantic North America is the Atlantic salmon, whereas the salmon and trout of the Pacific basin belong to another genus, '' ...

'' and ''

Salvelinus ''Salvelinus'' is a genus of salmonid fish often called char or charr; some species are called "trout". ''Salvelinus'' is a member of the subfamily Salmoninae within the family Salmonidae. The genus has a northern circumpolar distribution, and ...

'', all of the subfamily

Salmoninae Salmonidae is a family of ray-finned fish that constitutes the only currently extant family in the order Salmoniformes . It includes salmon (both Atlantic and Pacific species), trout (both ocean-going and landlocked), chars, freshwater whitefis ...

of the family

Salmonidae Salmonidae is a family of ray-finned fish that constitutes the only currently extant family in the order Salmoniformes . It includes salmon (both Atlantic and Pacific species), trout (both ocean-going and landlocked), chars, freshwater whitefis ...

. The word ''trout'' is also used as part of the name of some non-salmonid fish such as ''Cynoscion nebulosus'', the

spotted seatrout ''Cynoscion nebulosus'', the spotted seatrout, also known as speckled trout, is a common estuarine fish found in the southern United States along coasts of Gulf of Mexico and the coastal Atlantic Ocean from Maryland to Florida. While most of thes ...

or speckled trout. Trout are closely related to

salmon Salmon () is the common name for several commercially important species of euryhaline ray-finned fish from the family Salmonidae, which are native to tributaries of the North Atlantic (genus ''Salmo'') and North Pacific (genus '' Oncorhy ...

and char (or charr): species termed salmon and char occur in the same genera as do fish called trout (''Oncorhynchus'' – Pacific salmon and trout, ''Salmo'' – Atlantic salmon and various trout, ''Salvelinus'' – char and trout).

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 ...

and most other trout live in freshwater lakes and rivers exclusively, while there are others, such as the

steelhead Steelhead, or occasionally steelhead trout, is the common name of the anadromous form of the coastal rainbow trout or redband trout (O. m. gairdneri). Steelhead are native to cold-water tributaries of the Pacific basin in Northeast Asia and ...

, a form of the coastal rainbow trout, that can spend two or three years at sea before returning to fresh water to

spawn Spawn or spawning may refer to: * Spawn (biology), the eggs and sperm of aquatic animals Arts, entertainment, and media * Spawn (character), a fictional character in the comic series of the same name and in the associated franchise ** '' Spawn: ...

(a habit more typical of salmon). Arctic char and brook trout are part of the char genus. Trout are an important food source for humans and wildlife, including

brown bear The brown bear (''Ursus arctos'') is a large bear species found across Eurasia and North America. In North America, the populations of brown bears are called grizzly bears, while the subspecies that inhabits the Kodiak Islands of Alaska is ...

birds of prey Birds of prey or predatory birds, also known as raptors, are hypercarnivorous bird species that actively hunt and feed on other vertebrates (mainly mammals, reptiles and other smaller birds). In addition to speed and strength, these predat ...

such as

eagle Eagle is the common name for many large birds of prey of the family Accipitridae. Eagles belong to several groups of genera, some of which are closely related. Most of the 68 species of eagle are from Eurasia and Africa. Outside this area, j ...

s, and other animals. They are classified as

oily fish Oily fish are fish species with oil (fats) in soft tissues and in the coelomic cavity around the gut. Their fillets may contain up to 30% oil, although this figure varies both within and between species. Examples of oily fish include smal ...

Species

The name "trout" is commonly used for many (if not most) species in three of the seven genera in the subfamily Salmoninae: ''

'' (

Atlantic The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe an ...

), '' Oncorhynchus'' (

Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the contine ...

) and ''

'' ( circum-

arctic The Arctic ( or ) is a polar region located at the northernmost part of Earth. The Arctic consists of the Arctic Ocean, adjacent seas, and parts of Canada (Yukon, Northwest Territories, Nunavut), Danish Realm (Greenland), Finland, Iceland, N ...

). Fish species referred to as trout include: Marble trout from zadlaščica

* Genus ''

'', all extant species except Atlantic salmon **

Adriatic trout ''Salmo obtusirostris'', also known as the Adriatic trout, Adriatic salmon, and softmouth trout, is a species of salmonid fish endemic to the rivers of Western Balkans in southeastern Europe. The scientific name has changed several times thro ...

, ''Salmo obtusirostris'' ** Brown trout, ''Salmo trutta'' ***

River trout ''Salmo trutta fario'', sometimes called the river trout, and also known by the name of its parent species, the brown trout, is a predatory fish of the family Salmonidae and a subspecies or morph of the brown trout species, '' Salmo trutta'', w ...

, ''S. t.'' morpha ''fario'' *** Lake trout/Lacustrine trout, ''S. t''. morpha ''lacustris'' *** Sea trout, ''S. t.'' morpha ''trutta'' **

Flathead trout ''Salmo platycephalus'', known as the flathead trout,Tarkan, AN et al. (2008Threatened fishes of the world: ''Salmo platycephalus'' Behnke, 1968 (Salmonidae)''Environ. Biol. Fishes'' 81, 371-372. Ala balik or the Turkish trout, is a type of t ...

, ''Salmo platycephalus'' ** Marble trout, Soca River trout or Soča trout – ''Salmo marmoratus'' **

Ohrid trout Ohrid trout or the Lake Ohrid brown trout
Balkan trout restoration group. Downloaded on 20 May 2010. (''Sal ...

, ''Salmo letnica, S. balcanicus (extinct), S. lumi, and S. aphelios'' **

Sevan trout The Sevan trout (''Salmo ischchan'') is an endemic fish species of Lake Sevan in Armenia, known as ishkhan (իշխան, ) in Armenian. It is a salmonid fish related to the brown trout. The fish is endangered, because various competitors were ...

, ''Salmo ischchan'' Rainbow Trout

* Genus '' Oncorhynchus'', six of the 12 extant species **

Apache trout The Apache trout, ''Oncorhynchus apache'', is a species of freshwater fish in the salmon family (biology), family (family Salmonidae) of order (biology), order Salmoniformes. It is one of the Pacific trouts. Description The Apache trout measur ...

, ''Oncorhynchus apache'' **

Biwa trout The Biwa trout (''Oncorhynchus rhodurus'') is an anadromous salmonid fish of the genus ''Oncorhynchus'', endemic to Lake Biwa in Shiga Prefecture, Japan, but also introduced to Lake Ashi and Lake Chūzenji. While called trout, the fish is most ...

, ''Oncorhynchus masou rhodurus'' ** Cutthroat trout, ''Oncorhynchus clarki'' *** Coastal cutthroat trout, ''O. c. clarki'' **** Crescenti trout, ''O. c. c.'' f. crescenti *** Alvord cutthroat trout, ''O. c. alvordensis'' (extinct) ***

Bonneville cutthroat trout The Bonneville cutthroat trout (''Oncorhynchus clarkii utah'') is a subspecies of cutthroat trout native to tributaries of the Great Salt Lake and Sevier Lake. Most of the fish's current and historic range is in Utah, but they are also found in ...

, ''O. c. utah'' *** Humboldt cutthroat trout, ''O. c. humboldtensis'' ***

Lahontan cutthroat trout Lahontan cutthroat trout (''Oncorhynchus clarkii henshawi'') is the largest subspecies of cutthroat trout, and the state fish of Nevada. It is one of three subspecies of cutthroat trout that are listed as federally threatened. Natural history ...

, ''O. c. henshawi'' **** Whitehorse Basin cutthroat trout *** Paiute cutthroat trout, ''O. c. seleniris'' ***

Snake River fine-spotted cutthroat trout The Snake River fine-spotted cutthroat trout is a form of the cutthroat trout (''Oncorhynchus clarkii'') that is considered either as a separate subspecies ''O. c. behnkei'', or as a variety of the Yellowstone cutthroat trout (''O. c. bouvier ...

, ''O. c. behnkei'' ***

Westslope cutthroat trout The westslope cutthroat trout (''Oncorhynchus clarkii lewisi''), also known as the black-spotted trout, common cutthroat trout and red-throated trout is a subspecies of the cutthroat trout (''Oncorhynchus clarkii'') and is a freshwater fish in t ...

, ''O. c. lewisi'' ***

Yellowfin cutthroat trout The yellowfin cutthroat trout (''Oncorhynchus clarkii macdonaldi'') is an extinct subspecies or variety of the cutthroat trout, a North American freshwater fish. Natural history At the end of the last ice-age boulders and clay moraine blocke ...

, ''O. c. macdonaldi'' (extinct) *** Yellowstone cutthroat trout, ''O. c. bouvieri'' ***

Colorado River cutthroat trout The Colorado River cutthroat trout (''Oncorhynchus clarki pleuriticus'') is a subspecies of cutthroat trout native only to the Green and Colorado River basins, which are west of the Continental Divide. Cutthroat trout found in other river basins ...

, ''O. c. pleuriticus'' ***

Greenback cutthroat trout The greenback cutthroat trout (''Oncorhynchus clarkii stomias'') is the easternmost subspecies of cutthroat trout. The greenback cutthroat, once widespread in the Arkansas and South Platte River drainages of Eastern Colorado and Southeast Wyomin ...

, ''O. c. stomias'' ***

Rio Grande cutthroat trout The Rio Grande cutthroat trout (''Oncorhynchus clarki virginalis''), a member of the family Salmonidae, is found in northern New Mexico and southern Colorado in tributaries of the Rio Grande. It is one of 14 subspecies of cutthroat trout nat ...

, ''O. c. virginalis'' ** Gila trout, ''Oncorhynchus gilae'' ** Rainbow trout, ''Oncorhynchus mykiss'' *** Kamchatkan rainbow trout, '' Oncorhynchus mykiss mykiss'' ***

Columbia River redband trout The Columbia River redband trout, the inland redband trout or the interior redband troutCoastal rainbow trout (

), '' Oncorhynchus mykiss irideus'' ****

Beardslee trout The Beardslee trout (''Oncorhynchus mykiss irideus'' f. ''beardsleei''), formerly ''Salmo gairdneri beardsleei'') is a local form of rainbow trout endemic to Lake Crescent in Washington. Some sources treat them as a subspecies. Known to locals a ...

, '' Oncorhynchus mykiss irideus var. beardsleei'' ***

Great Basin redband trout The Great Basin redband trout (''Oncorhynchus mykiss newberrii'') is one of three redband trout subspecies of the rainbow trout in the western United States. The Great Basin redband trout is native to drainages in south central Oregon east of t ...

, ''Oncorhynchus mykiss newberrii'' ***

Golden trout The California golden trout (''Oncorhynchus aguabonita or Oncorhynchus mykiss aguabonita''), is a species of trout native to California. The golden trout is normally found in the Golden Trout Creek (tributary to the Kern River), Volcano Creek (t ...

, ''Oncorhynchus mykiss aguabonita'' **** Kern River rainbow trout, '' Oncorhynchus mykiss aguabonita var. gilberti'' **** Sacramento golden trout, '' Oncorhynchus mykiss aguabonita var. stonei'' **** Little Kern golden trout, '' Oncorhynchus mykiss aguabonita var. whitei'' *** Kamloops rainbow trout, '' Oncorhynchus mykiss kamloops'' ***

Baja California rainbow trout The Baja California rainbow trout or San Pedro Martir trout or Nelson's trout ('' Oncorhynchus mykiss nelsoni'') is a localized subspecies of the rainbow trout (''Oncorhynchus mykiss''), a freshwater fish in the family Salmonidae. Baja Californi ...

, Nelson's trout, or San Pedro Martir trout, '' Oncorhynchus mykiss nelsoni'' ***

Eagle Lake trout Eagle Lake trout, ''Oncorhynchus mykiss aquilarum'', is a subspecies of rainbow trout endemic to Eagle Lake, in Lassen County, California. It is a type of trout known for its ability to withstand high alkalinity.http://stevenojai.tripod.com/elra ...

, '' Oncorhynchus mykiss aquilarum'' *** McCloud River redband trout, '' Oncorhynchus mykiss stonei'' *** Sheepheaven Creek redband trout **

Mexican golden trout The Mexican golden trout (''Oncorhynchus chrysogaster'') is a species of fish in the family Salmonidae. The species is endemic to high-elevation headwaters of the Fuerte River, Sinaloa River, and Culiacán River drainages in the Sierra Madre Occ ...

, ''Oncorhynchus chrysogaster'' Brook trout 1918

* Genus ''

'', five of the 52 extant species ** Brook trout, ''Salvelinus fontinalis'' ***

Aurora trout The aurora trout, ''Salvelinus fontinalis timagamiensis'', is a variant or subspecies of the brook trout native to two lakes in the Temagami District of Ontario, Canada. The existence of the fish was brought to the attention of the angling world ...

, ''S. f. timagamiensis'' **

Bull trout The bull trout (''Salvelinus confluentus'') is a char of the family Salmonidae native to northwestern North America. Historically, ''S. confluentus'' has been known as the " Dolly Varden" (''S. malma''), but was reclassified as a separate speci ...

, ''Salvelinus confluentus'' **

Dolly Varden trout The Dolly Varden trout (''Salvelinus malma'') is a species of salmonid fish native to cold-water tributaries of the Pacific Ocean in Asia and North America. It belongs to the genus '' Salvelinus'', or true chars, which includes 51 recognized ...

, ''Salvelinus malma'' **

, ''Salvelinus namaycush'' **

Silver trout :''The name "silver trout" is also sometimes used for rainbow trout.'' The silver trout (''Salvelinus agassizii'') is an extinct char species or variety that inhabited a few waters in New Hampshire prior to 1939, when a biological survey conducte ...

, † ''Salvelinus agassizi'' (extinct) *Hybrids **

Tiger trout The tiger trout (''Salmo trutta'' × ''Salvelinus fontinalis'') is a sterile, intergeneric hybrid of the brown trout (''Salmo trutta'') and the brook trout (''Salvelinus fontinalis''). Pronounced vermiculations in the fish's patterning gave ri ...

, ''Salmo trutta X Salvelinus fontinalis'' (infertile) ** Speckled Lake (

Splake The splake or slake (''Salvelinus namaycush x Salvelinus fontinalis'') is a hybrid of two fish species resulting from the crossing of a male brook trout (''Salvelinus fontinalis'') and a female lake trout (''Salvelinus namaycush''). The name it ...

) trout, ''Salvelinus namaycush X Salvelinus fontinalis'' (fertile)

Fish from other families

*Pseudaphritidae ** Genus ''Pseudaphritis'' *** Sand trout, ''Pseudaphritis urvillii'' *

Sciaenidae Sciaenidae are a family of fish in the order Acanthuriformes. They are commonly called drums or croakers in reference to the repetitive throbbing or drumming sounds they make. The family consists of about 286 to 298 species in about 66 to 70 gene ...

** Genus ''Cynoscion'' *** Spotted sea-trout, ''Cynoscion nebulosus''

Anatomy

Trout that live in different environments can have dramatically different colorations and patterns. Mostly, these colors and patterns form as

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 b ...

, based on the surroundings, and will change as the fish moves to different habitats. Trout in, or newly returned from the sea, can look very silvery, while the same fish living in a small stream or in an alpine lake could have pronounced markings and more vivid coloration; it is also possible that in some species, this signifies that they are ready to mate. In general, trout that are about to breed have extremely intense coloration and can look like an entirely different fish outside of spawning season. It is virtually impossible to define a particular color pattern as belonging to a specific breed; however, in general, wild fish are claimed to have more vivid colors and patterns. Trout have fins entirely without spines, and all of them have a small

adipose Adipose tissue, body fat, or simply fat is a loose connective tissue composed mostly of adipocytes. In addition to adipocytes, adipose tissue contains the stromal vascular fraction (SVF) of cells including preadipocytes, fibroblasts, vascular ...

fin along the back, near the tail. The pelvic fins sit well back on the body, on each side of the anus. The swim bladder is connected to the

esophagus The esophagus ( American English) or oesophagus (British English; both ), non-technically known also as the food pipe or gullet, is an organ in vertebrates through which food passes, aided by peristaltic contractions, from the pharynx to ...

, allowing for gulping or rapid expulsion of air, a condition known as physostome. Unlike many other physostome fish, trout do not use their bladder as an auxiliary device for

oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as ...

uptake, relying solely on their

gills A gill () is a respiratory organ that many 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 ...

. There are many species, and even more populations, that are isolated from each other and morphologically different. However, since many of these distinct populations show no significant genetic differences, what may appear to be a large number of species is considered a much smaller number of distinct species by most

ichthyologists Ichthyology is the branch of zoology devoted to the study of fish, including bony fish (Osteichthyes), cartilaginous fish (Chondrichthyes), and jawless fish (Agnatha). According to FishBase, 33,400 species of fish had been described as of October ...

. The trout found in the eastern

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...

are a good example of this. The brook trout, the

aurora trout The aurora trout, ''Salvelinus fontinalis timagamiensis'', is a variant or subspecies of the brook trout native to two lakes in the Temagami District of Ontario, Canada. The existence of the fish was brought to the attention of the angling world ...

, and the (extinct)

silver trout :''The name "silver trout" is also sometimes used for rainbow trout.'' The silver trout (''Salvelinus agassizii'') is an extinct char species or variety that inhabited a few waters in New Hampshire prior to 1939, when a biological survey conducte ...

all have physical characteristics and colorations that distinguish them, yet

gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ...

tic analysis shows that they are one species, ''Salvelinus fontinalis''.

(''Salvelinus namaycush''), like brook trout, belong to the char genus. Lake trout inhabit many of the larger lakes in North America, and live much longer than rainbow trout, which have an average maximum lifespan of seven years. Lake trout can live many decades, and can grow to more than .

Habitat

Trout are usually found in cool (), clear streams and lakes, although many of the species have anadromous strains as well. Young trout are referred to as troutlet, troutling or fry. They are distributed naturally throughout North America, northern

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an are ...

and

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located entirel ...

. Several species of trout were introduced to Australia and

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

by amateur fishing enthusiasts in the 19th century, effectively displacing and endangering several upland native fish species. The introduced species included brown trout from England and rainbow trout from

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...

. The rainbow trout were a steelhead strain, generally accepted as coming from

Sonoma Creek , name_etymology = , image = Beaver Dam Sonoma Creek, Sonoma Thanksgiving 2009.jpg , image_caption = Beaver dam on Sonoma Creek at Maxwell Farms Regional Park in Sonoma, California, 2009 , image_size = 300 , ma ...

. The rainbow trout of New Zealand still show the steelhead tendency to run up rivers in winter to spawn. In Australia the rainbow trout was introduced in 1894 from New Zealand and is an extremely popular gamefish in recreational angling. Despite severely impacting the distribution and abundance of native Australian fish, such as the

climbing galaxias The climbing galaxias or kōaro (''Galaxias brevipinnis'') is a fish of the family Galaxiidae found in Australia, New Zealand, and nearby islands. The name climbing galaxias is used in Australia, and koaro or kōaro in New Zealand. Further verna ...

, millions of rainbow and other trout species are released annually from government and private hatcheries. The closest resemblance of seema trout and other trout family can be found in the Himalayan Region of India, Nepal, Bhutan, Pakistan and in

Tian Shan The Tian Shan,, , otk, 𐰴𐰣 𐱅𐰭𐰼𐰃, , tr, Tanrı Dağı, mn, Тэнгэр уул, , ug, تەڭرىتاغ, , , kk, Тәңіртауы / Алатау, , , ky, Теңир-Тоо / Ала-Тоо, , , uz, Tyan-Shan / Tangritog‘ ...

mountains of

Kyrgyzstan Kyrgyzstan,, pronounced or the Kyrgyz Republic, is a landlocked country in Central Asia. Kyrgyzstan is bordered by Kazakhstan to the north, Uzbekistan to the west, Tajikistan to the south, and the People's Republic of China to the ea ...

Diet

Trout generally feed on other fish, and soft bodied aquatic

invertebrate Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...

s, such as

flies Flies are insects of the order Diptera, the name being derived from the Greek δι- ''di-'' "two", and πτερόν ''pteron'' "wing". Insects of this order use only a single pair of wings to fly, the hindwings having evolved into advanced m ...

mayflies Mayflies (also known as shadflies or fishflies in Canada and the upper Midwestern United States, as Canadian soldiers in the American Great Lakes region, and as up-winged flies in the United Kingdom) are aquatic insects belonging to the order ...

caddisflies The caddisflies, or order Trichoptera, are a group of insects with aquatic larvae and terrestrial adults. There are approximately 14,500 described species, most of which can be divided into the suborders Integripalpia and Annulipalpia on the ...

, stoneflies,

mollusk Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is e ...

s and

dragonflies A dragonfly is a flying insect belonging to the infraorder Anisoptera below the order Odonata. About 3,000 extant species of true dragonfly are known. Most are tropical, with fewer species in temperate regions. Loss of wetland habitat threa ...

. In lakes, various species of

zooplankton Zooplankton are the animal component of the planktonic community ("zoo" comes from the Greek word for ''animal''). Plankton are aquatic organisms that are unable to swim effectively against currents, and consequently drift or are carried along by ...

often form a large part of the diet. In general, trout longer than about prey almost exclusively on fish, where they are available. Adult trout will devour smaller fish up to 1/3 their length. Trout may feed on shrimp,

mealworm Mealworms are the larval form of the yellow mealworm beetle, ''Tenebrio molitor'', a species of darkling beetle. Like all holometabolic insects, they go through four life stages: egg, larva, pupa, and adult. Larvae typically measure about or ...

s, bloodworms,

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three ...

s, small animal parts, and

eel Eels are ray-finned fish belonging to the order Anguilliformes (), which consists of eight suborders, 19 families, 111 genera, and about 800 species. Eels undergo considerable development from the early larval stage to the eventual adult stage ...

. Trout who swim the streams love to feed on land animals, aquatic life, and flies. Most of their diet comes from macroinvertebrates, or animals that do not have a backbone like snails, worms, or insects. They also eat flies, and most people who try to use lures to fish trout mimic flies because they are one of trout's most fed on meals. Trout enjoy certain land animals, including insects like grasshoppers. They also eat small animals like mice when they fall in. (Although only large trout have mouths capable of eating mice.) They consume a diet of aquatic life like minnows or crawfish as well. Trout have a diverse diet they follow; they have plenty of different oppositions.

As food

As a group, trout are somewhat bony, but the flesh is generally considered to be tasty. The flavor of the flesh is heavily influenced by the diet of the fish. For example, trout that have been feeding on crustaceans tend to be more flavorful than those feeding primarily on insect life. Additionally, they provide a good fight when caught with a

hook A hook is a tool consisting of a length of material, typically metal, that contains a portion that is curved or indented, such that it can be used to grab onto, connect, or otherwise attach itself onto another object. In a number of uses, one e ...

and line, and are sought after recreationally. Because of their popularity, trout are often raised on fish farms and planted into heavily fished waters, in an effort to mask the effects of overfishing. Farmed trout and char are also sold commercially as

food fish Food is any substance consumed by an organism for nutritional support. Food is usually of plant, animal, or fungal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals. The substance is ing ...

. Trout is sometimes prepared by smoking. One fillet of trout (79 g) contains: * Energy : * Fat (g): 5.22 * Carbohydrates (g): 0 * Fibers (g): 0 * Protein (g): 16.41 * Cholesterol (mg): 46

Trout fishing

River fishing

While trout can be caught with a normal rod and

reel A reel is an object around which a length of another material (usually long and flexible) is wound for storage (usually hose are wound around a reel). Generally a reel has a cylindrical core (known as a '' spool'') with flanges around the ends ...

, fly fishing is a distinctive method developed primarily for trout, and now extended to other species. Understanding how moving water shapes the stream channel makes it easier to find trout. In most streams, the current creates a riffle-run-pool pattern that repeats itself over and over. A deep pool may hold a big brown trout, but rainbows and smaller browns are likely found in runs.

Riffle A riffle is a shallow landform in a flowing channel. Colloquially, it is a shallow place in a river where water flows quickly past rocks. However, in geology a riffle has specific characteristics. Topographic, sedimentary and hydraulic indica ...

s are where fishers will find small trout, called troutlet, during the day and larger trout crowding in during morning and evening feeding periods. * Riffles have a fast current and shallow water. This gives way to a bottom of gravel, rubble or boulder. Riffles are morning and evening feeding areas. Trout usually spawn just above or below riffles, but may spawn right in them. * Runs are deeper than riffles with a moderate current and are found between riffles and pools. The bottom is made up of small gravel or rubble. These hot spots hold trout almost anytime, if there is sufficient cover. * Pools are smoother and look darker than the other areas of the stream. The deep, slow-moving water generally has a bottom of silt, sand, or small gravel. Pools make good midday resting spots for medium to large trout. * It is recommended that when fishing for trout, that the fisher(s) should use line in the 4–8 lb test for streamfish, and stronger line with the same diameter for trout from the sea or from a large lake, such as Lake Michigan. It is also recommended to use a hook size 8-5 for trout of all kind. Trout, especially farm-raised ones, tend to like

salmon roe Red caviar is a caviar made from the roe of salmonid fishes (various species of salmon and trout), which has intense reddish hue. It is distinct from black caviar, which is made from the roe of sturgeon.Nichola Fletcher, ''Caviar: A Global Hi ...

worm Worms are many different distantly related bilateral animals that typically have a long cylindrical tube-like body, no limbs, and no eyes (though not always). Worms vary in size from microscopic to over in length for marine polychaete wo ...

minnow Minnow is the common name for a number of species of small freshwater fish, belonging to several genera of the families Cyprinidae and Leuciscidae. They are also known in Ireland as pinkeens. Smaller fish in the subfamily Leusciscidae are c ...

s, cut bait,

maize Maize ( ; ''Zea mays'' subsp. ''mays'', from es, maíz after tnq, mahiz), also known as corn (North American and Australian English), is a cereal grain first domesticated by indigenous peoples in southern Mexico about 10,000 years ago. The ...

, or

marshmallow Marshmallow (, ) is a type of confectionery that is typically made from sugar, water and gelatin whipped to a solid-but-soft consistency. It is used as a filling in baking or normally molded into shapes and coated with corn starch. The sugar c ...

Ice fishing

Fishing for trout under the ice generally occurs in depths of 4 to 8 feet. Because trout are cold water fish, during the winter they move from up-deep to the shallows, replacing the small fish that inhabit the area during the summer. Trout in winter constantly cruise in shallow depths looking for food, usually traveling in groups, although bigger fish may travel alone and in water that's somewhat deeper, around 12 feet. Rainbow, Brown, and Brook trout are the most common trout species caught through the ice.

Trout fishing records

By information from

International Game Fish Association The International Game Fish Association (''IGFA'') is the leading authority on angling pursuits and the keeper of the most current World Record fishing catches by fish categories. Fishermen who are sport fishers are careful to follow their string ...

(IGFA), the most outstanding records are: * Brook trout caught by Dr. W. Cook in the Nipigon River, Canada, on July 1, 1916, that weighed 6.57 kg (14 lbs. 8 oz.) * Cutthroat trout caught by John Skimmerhorn in Pyramid Lake located in Nevada, US, on December 1, 1925, that weighed 18.59 kg (41 lbs. 0 oz.) *

caught by N. Higgins in Lake Pend Oreille located in Idaho, US, on October 27, 1949, that weighed 14.51 kg (32 lbs. 0 oz.) *

caught by Chas Reed in Cooks Lake located in Wyoming, US, on August 5, 1948, that weighed 4.98 kg (11 lbs. 0 oz.) * Rainbow trout caught by Sean Konrad in Lake Diefenbaker, Canada, on September 5, 2009, that weighed 21.77 kg (48 lbs. 0 oz.) *

caught by Lloyd Bull in Great Bear Lake, Canada, on August 19, 1995, that weighed 32.65 kg (72 lbs. 0 oz.)

Fishing baits

File:Achroia grisella caterpillars kleine wasmot rupsen (1).jpg,

Waxworm Waxworms are the caterpillar larvae of wax moths, which belong to the family Pyralidae (snout moths). Two closely related species are commercially bred – the lesser wax moth (''Achroia grisella'') and the greater wax moth (''Galleria ...

s are used as live-bait for trout fishing. File:Corn borer.jpg, Corn worms are also excellent live-bait when trout fishing. File:Plecoptera.jpg,

Nymph A nymph ( grc, νύμφη, nýmphē, el, script=Latn, nímfi, label= Modern Greek; , ) in ancient Greek folklore is a minor female nature deity. Different from Greek goddesses, nymphs are generally regarded as personifications of nature, are ...

of a golden stonefly are used as live-bait for trout fishing. File:Ecdyonurus tobiironis Kurotanigawakagerou larva.jpg,

mayfly File:Ikorka.jpg,

Salmon roe Red caviar is a caviar made from the roe of salmonid fishes (various species of salmon and trout), which has intense reddish hue. It is distinct from black caviar, which is made from the roe of sturgeon.Nichola Fletcher, ''Caviar: A Global Hi ...

( red caviar) File:Jyväskylä - worm.jpg, Worms are cheap and effective bait to use for trout and most types of fish. File:MoscaWoolyBugger.jpg, Wooly buggers can be tied in every color imaginable. File:Pink-roe-egg-fly 02.jpg, Egg patterns are effective for steelhead and trout in rivers. File:Muddler minnow fly.JPG, Muddler minnow

Declines in native trout populations

Salmonid populations in general have been declining due to numerous factors, including invasive species, hybridization, wildfires, and climate change. Native salmonid fish in the western and southwestern United States are threatened by non-native species that were introduced decades ago. Non-native salmonids were introduced to enrich recreational fishing; however, they quickly started outcompeting and displacing native salmonids upon their arrival. Non-native, invasive species are quick to adapt to their new environment and learn to outcompete any native species, making them a force the native salmon and trout have to reckon with. Not only do the non-native fish drive the native fish to occupy new niches, but they also try to hybridize with them, contaminating the native gene construction. As more hybrids between native and non-native fish are formed, the lineage of the pure fish is continuously being contaminated by other species and soon may no longer represent the sole native species. The Rio Grande Cutthroat trout ( ''Oncorhynchus clarki virginalis'') are susceptible to hybridization with other salmonids such as rainbow trout ( ''Oncorhynchus mykiss'') and yield a new "cut-bow" trout, which is a contamination of both lineages’ genes. One solution to this issue is implemented by New Mexico Game and Fish hatcheries: stock only sterile fish in river streams. Hatcheries serve as a reservoir of fish for recreational activities but growing and stocking non-sterile fish would worsen the hybridization issue on a quicker, more magnified time scale. By stocking sterile fish, the native salmonids can't share genes with the non-native hatchery fish, thus, preventing further gene contamination of the native trout in New Mexico. Fire is also a factor in deteriorating Gila trout ( ''Oncorhynchus gilae'') populations because of the ash and soot that can enter streams following fires. The ash lowers water quality, making it more difficult for the Gila trout to survive. In some New Mexico streams, the native Gila trout will be evacuated from streams that are threatened by nearby fires and be reintroduced after the threat is resolved.

Climate change In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to ...

is also dwindling native salmonid populations. Climate change continually affects various cold-water fish, including trout. With an increase of temperature along with changes in spawning river flow, an abundance of trout species are effected negatively. In the past, a mere 8 °F increase was predicted to eliminate half of the native brook trout in the Southern Appalachian Mountains. Trout prefer cold water (50-60 °F) streams to spawn and live, but warming water temperatures are altering this ecosystem and further deteriorate native populations.

References

External links

*
Trout.co.uk
– Website focused purely on fishing for trout
Trout Unlimited
– Conserving, protecting and restoring North America's coldwater fisheries and their watersheds
"Trout Science,"
www.troutlet.com, 2000. {{Authority control Fish common names Salmonidae Cold water fish Commercial fish Oily fish Smoked fish Sport fish Holarctic fauna