dcsimg

Lifespan, longevity, and ageing

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Maximum longevity: 38 years Observations: These animals normally do not live more than 6 years (Das 1994). In some cases, such as the ferox trout, animals may start preying other fishes and growing much faster, and end up living longer as well.
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Untitled

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Some brown trout have been reported to reach weights of up to thirty pounds (13.6 kg) and lengths of three feet (91 cm).

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Idema, A. 1999. "Salmo trutta" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Salmo_trutta.html
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Andrew Idema, University of Michigan-Ann Arbor
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Behavior

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Communication Channels: visual ; tactile ; chemical

Perception Channels: visual ; tactile ; chemical

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Idema, A. 1999. "Salmo trutta" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Salmo_trutta.html
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Conservation Status

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Brown trout are an abundant and widespread species, and so are not considered in need of special conservation efforts to preserve the species as a whole. Since they are a popular game fish, they are often protected by local fishing regulations.

US Federal List: no special status

CITES: no special status

State of Michigan List: no special status

IUCN Red List of Threatened Species: least concern

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Idema, A. 1999. "Salmo trutta" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Salmo_trutta.html
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Benefits

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When introduced outside their native range, brown trout compete with and prey upon native trout and other fish and amphibian species. Introduction of brown trout has been associated with declines in native brook trout in the eastern U.S. and frog species in the west. In some locations, brown trout may act as a prey base for parasitic sea lampreys (Petromyzon marinus). This may increase lamprey pressure on other native species. Introductions of brown trout may also bring fish diseases that can attack native species as well.

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Idema, A. 1999. "Salmo trutta" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Salmo_trutta.html
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Benefits

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The main economic benefit of brown trout is the sport of fishing for the species. Many people pursue the sport fishing and some flyfish for browns. Many fisherman donate money to conservation groups to keep the sport alive. Also, browns make a delicious meal.

Positive Impacts: food ; ecotourism

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Idema, A. 1999. "Salmo trutta" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Salmo_trutta.html
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Trophic Strategy

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Smaller brown trout feed primarily on insects. The most important insects vary with the season but the bulk of them are mayflies, caddisflies, midges or terrestrial insects. Browns in smaller streams are also dependent on food washed from the banks. Small browns select an area for feeding in a drift and do not move from it until a predator is introduced. This foraging site is characterized by a good view of the drift near refuge sites such as deep water or complex structure. Small browns never feed immediately upstream of a larger fish. Large browns' diets are more diverse than that of younger browns. Smaller trout account for 80% of the large brown's diet. The remaining diet consists of large aquatic insects such as Hexagania and Brown Drake (Ephemera simulans) mayflies and larger species of caddisflies (Trichoptera), crustaceans, snails, amphibians, and food washed from the bank. Also, the feeding habits of large browns is primarily nocturnal. They eat whatever is in the immediate area, preferably about 4 inches from the stream's floor in riffles, pools, or eddies. In contrast to young browns, large brown trout do not sit and wait for food, they hunt it actively.

Animal Foods: fish; insects; terrestrial non-insect arthropods; aquatic crustaceans; zooplankton

Primary Diet: carnivore (Piscivore , Insectivore )

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Idema, A. 1999. "Salmo trutta" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Salmo_trutta.html
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Distribution

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Brown trout are native to Europe. The species is found in Iceland and on the Northwest coast of Europe, along the Mediterranean and south to India. They have been introduced to appropriate streams all over the world.

Biogeographic Regions: nearctic (Introduced ); palearctic (Native ); oriental (Introduced ); ethiopian (Introduced ); neotropical (Introduced ); australian (Introduced )

Other Geographic Terms: cosmopolitan

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Idema, A. 1999. "Salmo trutta" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Salmo_trutta.html
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Habitat

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The species can live in a higher temperature than most other trouts, and this is probably why they were introduced to North America. They are a succesful and aggressive species who are permanent residents in most of the regions where they have been released.

Habitat Regions: temperate ; freshwater

Aquatic Biomes: rivers and streams

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Idema, A. 1999. "Salmo trutta" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Salmo_trutta.html
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Life Expectancy

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Average lifespan
Status: wild:
11.0 years.

Average lifespan
Status: wild:
8.0 years.

Average lifespan
Status: captivity:
10.0 years.

Average lifespan
Status: wild:
18.0 years.

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Idema, A. 1999. "Salmo trutta" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Salmo_trutta.html
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Andrew Idema, University of Michigan-Ann Arbor
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Morphology

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Adult browns are generally 13 to 16 inches (33-40.6 cm) in length, although old individuals can reach a much larger size. Their bodies are olive brown or green shading to a yellowish white on the belly. The sides of the fish have beautiful red spots surrounded by a pale halo.

Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry

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Idema, A. 1999. "Salmo trutta" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Salmo_trutta.html
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Andrew Idema, University of Michigan-Ann Arbor
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Reproduction

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When brown trout spawn, the male and female are not monogamous. These trout mate every year, and they are not likely to have the same mate year after year. Occasionally, large males take over a bed already occupied by a smaller, less aggressive trout.

Mating System: polygynandrous (promiscuous)

Brown trout mature at about 3 or 4 years of age. They spawn in the fall from October into December. When they spawn, they head into shallow headwater brooks of the river. The female scoops out a hollow on a gravel "redd" where she can lay her eggs. As she releases the eggs on the redd, the male simultaneously releases milt to fertilize them. The pair continues this process until all of the female's eggs are spent. The female then covers the fertilized eggs with sand or gravel for protection. The eggs are then left to develop and hatch the following spring. Browns do not necessarily come back to the same gravel bed to spawn each year, but they come back to the same general area of the river.

Key Reproductive Features: semelparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (External ); oviparous

Average number of offspring: 8000.

Female brown trout invest nutrients in yolk for eggs, but do not provide any care after the eggs are laid. Male brown trout provide no investment in offspring after fertilization.

Parental Investment: pre-fertilization (Provisioning)

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Idema, A. 1999. "Salmo trutta" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Salmo_trutta.html
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Andrew Idema, University of Michigan-Ann Arbor
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Biology

provided by Arkive
The brown trout is an economically important species, particularly due to its popularity with anglers, and stocks are maintained in many areas by artificial introductions (2). This fish feeds on invertebrates, insect larvae, aerial insects, and molluscs, as well as the occasional fish and frog (4). Spawning occurs between January and March, when females are accompanied by a number of males. The eggs, which are fertilised externally, are covered with gravel by the female. For the first days after hatching, the young fish (fry) derive their nutrients from their large yolk sacs; they then feed on small arthropods, such as insect larvae (2). The maximum-recorded life span of a brown trout is 5 years (4).
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Conservation

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No conservation action has been targeted at this species.
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Description

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The brown trout is a beautiful fish, similar in general shape to the salmon; the back is dark, the sides pale, and both are flecked with variable reddish spots that have pale borders (3). The belly is a creamy yellowish-white. Juveniles and immature adults can be distinguished as they have bluish-grey spots, and adult males have a strongly curved lower jaw (2).
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Habitat

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Inhabits well-oxygenated streams and rivers (3).
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Range

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The brown trout is found throughout Europe; those that live in rivers which empty into the North Sea and the Baltic Sea belong to the subspecies Salmo trutta fario, those that live in rivers that empty into the Black Sea are of the subspecies Salmo trutta labrax, and those in rivers emptying into the Mediterranean belong to the subspecies S. t. macrostigma (2). The brown trout (Salmo trutta fario) is found throughout the British Isles (3).
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Status

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Common and widespread (4).
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Threats

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Not currently threatened.
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Brief Summary

provided by Ecomare
Sea trout can grow to a maximum length of 1.4 meters and weight of 20 kilograms. Sometimes, a large sea trout is mistaken for salmon. However, sea trout is not as scarce as wild salmon. It eats gammarids, insects, lesser sandeel, herring and worms.
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Brief Summary

provided by EOL authors
Salmo trutta is a common trout known by two different common names reflecting the alternative ecological strategies and associated morphological characteristics of this species. The freshwater morphs (Salmo trutta morpha fario and S. trutta morpha lacustris) are known as brown trout. Sea trout is the anadromous morph which migrates between the ocean, where it spends most of its life, and freshwater spawning grounds. The two morphs, which often share the same breeding grounds (sympatric distribution), have in the past been classified as distinct species. The morphs do interbreed, but the extent of reproductive isolation between them varies by location and some studies have found genetic differentiation between morphs inhabiting the same territory. Although native to Europe, northern Africa and western Asia, S. trutta has been widely introduced for aquaculture and recreational fishing purposes and is found in streams, lakes, and coastal areas throughout the world. Brown trout commonly mature at 13-16 inches long (often longer in large streams); sea-run morphs are larger and can be found up to 30 pounds and 3 feet long. An aggressive species, S. trutta has been responsible for declines in native fish populations, for example in the Great Lakes, where they displaced Arctic greyling (Thymallus arcticus) and in California, where they threaten native golden trout Oncorhynchus mykiss aguabonita and Dolly Varden (Salvelinus malma). This species was nominated as one of the world’s 100 worst invasive species by the Invasive Species Specialist Group (ISSG). (CABI 2010;Charles et al 2005; Fuller, Larson and Fusaro 2012; Global Invasive Species Database, Invasive Species Specialist Group; Idema 1999; Wikipedia 2012)

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Diagnostic Description

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Fusiform body (Ref. 51442). Head little and pointed (Ref. 51442). Mouth large, extending mostly after the eye and has well developed teeth (Ref. 51442). Teeth on shaft of vomer numerous and strongly developed (Ref. 7251). Caudal fin with 18-19 rays (Ref. 2196). Caudal peduncle thick and rounded (Ref. 51442). Little scales (Ref. 51442). Body is grey-blue colored with numerous spots, also below the lateral line (Ref. 51442). Blackish colored on upper part of body, usually orange on sides, surrounded by pale halos. Adipose fin with red margin.
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Recorder
Rainer Froese
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Diseases and Parasites

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Enteric Redmouth Disease. Bacterial diseases
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Diseases and Parasites

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Hysterothylacium Infection 8. Parasitic infestations (protozoa, worms, etc.)
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Diseases and Parasites

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Camallanus Infection 16. Parasitic infestations (protozoa, worms, etc.)
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Diseases and Parasites

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Aeromonosis. Bacterial diseases
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Diseases and Parasites

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Hysterothylacium Infection (Hysterothylacium sp.). Parasitic infestations (protozoa, worms, etc.)
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Life Cycle

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Female covers the eggs by restirring the sand and fine gravel (Ref. 9696). After hatching at 12 mm, larval brown trout remain in the gravel for 2-3 weeks until they are about 25 mm long, when they emerge to begin feeding in the water column. Brown trout are territorial and begin establishing territories as juveniles. Juvenile trout from lake populations move from their natal inlets to lakes during the first 2 years of life (Ref. 6390).
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Migration

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Anadromous. Fish that ascend rivers to spawn, as salmon and hilsa do. Sub-division of diadromous. Migrations should be cyclical and predictable and cover more than 100 km.
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Susan M. Luna
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Morphology

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Dorsal spines (total): 3 - 4; Dorsal soft rays (total): 10 - 15; Anal spines: 3 - 4; Analsoft rays: 9 - 14; Vertebrae: 57 - 59
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Trophic Strategy

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Brown trout are territorial and begin establishing territories as juveniles (Ref. 26526). Juvenile trout from lake populations move from their natal inlets to lakes during the first 2 years of life (Ref. 6390). For sympatric populations of this species and Gadopsis marmoratus, coexistence was possible, although their diets were similar, because each species occupied different habitats (Ref. 26860). Juveniles feed mainly on larvae of insects; adults feed on crustaceans and fish (Ref. 51442). Fingerling brown trout seems to act as an opportunistic predator, and the consumption of different preys seems to be influenced by their accessibility, predation risk, and their energetic value (Ref. 55756). It is preyed upon by kingfishers and mergansers.
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Biology

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Found in streams, ponds, rivers and lakes (Ref. 5951). Individuals spend 1 to 5 years in fresh water and 6 months to 5 years in salt water (Ref. 51442). Juveniles mature in 3-4 years (Ref. 6885). Lacustrine populations undertake migration to tributaries and lake outlets to spawn, rarely spawning on stone, wave-washed lake shores. Spawns in rivers and streams with swift current, usually characterized by downward movement of water intro gravel (Ref. 59043). Spawning takes place normally more than one time (Ref. 51442). They prefer cold, well-oxygenated upland waters although their tolerance limits are lower than those of rainbow trout and favors large streams in the mountainous areas with adequate cover in the form of submerged rocks, undercut banks, and overhanging vegetation (Ref. 6465). Life history and spawning behavior is similar to the salmon Salmo salar (Ref. 51442). Each female produces about 10.000 eggs (Ref. 35388, Ref. 51442). Mainly diurnal (Ref. 682). Sea and lake trouts forage in pelagic and littoral habitats, while sea trouts mainly close to coast, not very far from estuary of natal river (Ref. 59043). Juveniles feed mainly on aquatic and terrestrial insects; adults on mollusks, crustaceans and small fish (Ref. 26523, Ref. 51442). Marketed fresh and smoked; eaten fried, broiled, boiled, cooked in microwave, and baked (Ref. 9988).
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Importance

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fisheries: commercial; aquaculture: commercial; gamefish: yes
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Brown trout

provided by wikipedia EN

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,[3][4] 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.[5] 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 streams, but sometimes in larger rivers. Anadromous and non-anadromous morphs coexisting in the same river appear genetically identical.[6] What determines whether or not they migrate remains unknown.

Taxonomy

The scientific name of the brown trout is Salmo trutta. The specific epithet trutta derives from the Latin trutta, meaning, literally, "trout". Behnke (2007) relates that the brown trout was the first species of trout described in the 1758 edition of Systema Naturae by Swedish zoologist Carl Linnaeus. Systema Naturae established the system of binomial nomenclature for animals. Salmo trutta was used to describe anadromous or sea-run forms of brown trout. Linnaeus also described two other brown trout species in 1758. Salmo fario was used for riverine forms. Salmo lacustris was used for lake-dwelling forms.[7]

Range

A sea trout jumping a weir in Wales

The native range of brown trout extends from northern Norway and White Sea tributaries in Russia in the Arctic Ocean to the Atlas Mountains in North Africa. The western limit of their native range is Iceland in the north Atlantic, while the eastern limit is in Aral Sea tributaries in Afghanistan and Pakistan.[8]

Introduction outside their natural range

Brown trout have been widely introduced into suitable environments around the world, including North and South America, Australasia, Asia, and South and East Africa. Introduced brown trout have established self-sustaining, wild populations in many introduced countries.[9] The first introductions were in Australia in 1864 when 300 of 1500 brown trout eggs from the River Itchen survived a four-month voyage from Falmouth, Cornwall, to Melbourne on the sailing ship Norfolk. By 1866, 171 young brown trout were surviving in a Plenty River hatchery in Tasmania. Thirty-eight young trout were released in the river, a tributary of the River Derwent in 1866. By 1868, the Plenty River hosted a self-sustaining population of brown trout which became a brood source for continued introduction of brown trout into Australian and New Zealand rivers.[10] Successful introductions into the Natal and Cape Provinces of South Africa took place in 1890 and 1892, respectively. By 1909, brown trout were established in the mountains of Kenya. The first introductions into the Himalayas in northern India took place in 1868, and by 1900, brown trout were established in Kashmir and Madras.[11]

Introduction to Americas

The first introductions in Canada occurred in 1883 in Newfoundland[12] and continued until 1933. The only Canadian regions without brown trout are Yukon and the Northwest Territories. Introductions into South America began in 1904 in Argentina. Brown trout are now established in Chile, Peru, and the Falklands.[10] In the 1950s and 1960s, Edgar Albert de la Rue, a French geologist, began the introduction of several species of salmonids on the remote Kerguelen Islands in the southern Indian Ocean. Of the seven species introduced, only brook trout, Salvelinus fontinalis, and brown trout survived to establish wild populations.[13] Sea-run forms of brown trout exceeding 20 lb (9.1 kg) are caught by local anglers on a regular basis.

Map of U.S. ranges of brown trout
U.S. range of brown trout

The first introductions into the U.S. started in 1883 when Fred Mather, a New York pisciculturist and angler, under the authority of the U.S. Fish Commissioner, Spencer Baird, obtained brown trout eggs from a Baron Lucius von Behr, president of the German Fishing Society. The von Behr brown trout came from both mountain streams and large lakes in the Black Forest region of Baden-Württemberg.[8] The original shipment of "von Behr" brown trout eggs were handled by three hatcheries, one on Long Island, the Cold Spring Hatchery operated by Mather, one in Caledonia, New York, operated by pisciculturalist Seth Green, and other hatchery in Northville, Michigan. Additional shipments of "von Behr" brown trout eggs arrived in 1884. In 1885, brown trout eggs from Loch Leven, Scotland, arrived in New York. These "Loch Leven" brown trout were distributed to the same hatcheries. Over the next few years, additional eggs from Scotland, England, and Germany were shipped to U.S. hatcheries. Behnke (2007) believed all life forms of brown trout—anadromous, riverine, and lacustrine—were imported into the U.S. and intermingled genetically to create what he calls the American generic brown trout and a single subspecies the North European brown trout (S. t. trutta).[8]

In April 1884, the U.S. Fish Commission released 4900 brown trout fry into the Baldwin River, a tributary of the Pere Marquette River in Michigan. This was the first release of brown trout into U.S. waters. Between 1884 and 1890, brown trout were introduced into suitable habitats throughout the U.S.[8] By 1900, 38 states and two territories had received stocks of brown trout. Their adaptability resulted in most of these introductions establishing wild, self-sustaining populations.[10]

Conservation status

 src=
Infographic about the brown trout.

The fish is not considered to be endangered, although some individual stocks are under various degrees of stress mainly through habitat degradation, overfishing, and artificial propagation leading to introgression. Increased frequency of excessively warm water temperatures in high summer causes a reduction in dissolved oxygen levels which can cause "summer kills" of local populations if temperatures remain high for sufficient duration and deeper/cooler or fast, turbulent more oxygenated water is not accessible to the fish. This phenomenon can be further exacerbated by eutrophication of rivers due to pollution—often from the use of agricultural fertilizers within the drainage basin.

Overfishing is a problem where anglers fail to identify and return mature female fish into the lake or stream. Each large female removed can result in thousands fewer eggs released back into the system when the remaining fish spawn.

Another threat is other introduced organisms. For example, in Canada's Bow River, a non-native alga Didymosphenia geminata—common name rock snot (due to appearance)—has resulted in reduced circulation of water amongst the substrate of the river bed in affected areas. This, in turn, can greatly reduce the number of trout eggs that survive to hatch. Over time, this leads to reduction of the population of adult fish in the areas affected by the algae, forming a circle of decline. Rock snot is believed to have spread accidentally on the soles of the footwear of visitors from areas where the alga is native. The wide variety of issues that adversely affect brown trout throughout its range do not exclusively affect brown trout, but affect many or all species within a water body, thus altering the ecosystem in which the trout reside.

In small streams, brown trout are important predators of macroinvertebrates, and declining brown trout populations in these specific areas affect the entire aquatic food web.[14]

Global climate change is also of concern. S. trutta morpha fario prefers well-oxygenated water in the temperature range of 60 to 65 °F (16 to 18 °C). S. trutta bones from an archaeological site in Italy, and ancient DNA extracted from some of these bones, indicate that both abundance and genetic diversity increased markedly during the colder Younger Dryas period, and fell during the warmer Bølling-Allerød event.[15]

Cover or structure is important to trout, and they are more likely to be found near submerged rocks and logs, undercut banks, and overhanging vegetation. Structure provides protection from predators, bright sunlight, and higher water temperatures. Access to deep water for protection in winter freezes, or fast water for protection from low oxygen levels in summer are also ideal. Trout are more often found in heavy and strong currents.

Characteristics

Defining characteristics include a slender, reddish-brown body with a long, narrow head.

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A 2.7-kg (6 lb), 60-cm (2 ft) sea trout, from Galway Bay in the west of Ireland bearing scars from a fishing net
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Brown trout in a creek
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Brown trout in Värmland, Sweden, after the first summer
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A young brown trout from the River Derwent in North East England
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Brown trout from a western Wyoming creek

The brown trout is a medium-sized fish, growing to 20 kg (44 lb) or more and a length of about 100 cm (39 in) in some localities, although in many smaller rivers, a mature weight of 1.0 kg (2.2 lb) or less is common. S. t. lacustris reaches an average length of 40–80 cm (16–31 in) with a maximum length of 140 cm (55 in) and about 60 pounds (27 kg). The spawning behaviour of brown trout is similar to that of the closely related Atlantic salmon. A typical female produces about 2,000 eggs per kg (900 eggs per lb) of body weight at spawning. On September 11, 2009, a 41.45-lb (18.80-kg) brown trout was caught by Tom Healy in the Manistee River system in Michigan, setting a new state record. As of late December 2009, the fish captured by Healy was confirmed by both the International Game Fish Association and the Fresh Water Fishing Hall of Fame as the new all-tackle world record for the species. This fish now supplants the former world record from the Little Red River in Arkansas.

Brown trout can live 20 years, but as with the Atlantic salmon, a high proportion of males die after spawning, and probably fewer than 20% of anadromous female kelts recover from spawning. The migratory forms grow to significantly larger sizes for their age due to abundant forage fish in the waters where they spend most of their lives. Sea trout are more commonly female in less nutrient-rich rivers. Brown trout are active both by day and by night and are opportunistic feeders. While in freshwater, their diets frequently include invertebrates from the streambed, other fish, frogs, mice, birds, and insects flying near the water's surface. The high dietary reliance upon insect larvae, pupae, nymphs, and adults allows trout to be a favoured target for fly fishing. Sea trout are fished for especially at night using wet flies. Brown trout can be caught with lures such as spoons, spinners, jigs, plugs, plastic worm imitations, and live or dead baitfish. Freshwater brown trout range in colour from largely silver with relatively few spots and a white belly, to the more well-known brassy brown cast fading to creamy white on the fish's belly, with medium-sized spots surrounded by lighter halos. The more silver forms can be mistaken for rainbow trout. Regional variants include the so-called "Loch Leven" trout, distinguished by larger fins, a slimmer body, and heavy black spotting, but lacking red spots. The continental European strain features a lighter golden cast with some red spotting and fewer dark spots. Notably, both strains can show considerable individual variation from this general description. Early stocking efforts in the United States used fish taken from Scotland and Germany.

Brown trout rarely form hybrids with other species; if they do, they are almost invariably infertile. One such example is the tiger trout, a hybrid with the brook trout.

Diet

Field studies have demonstrated that brown trout fed on several animal prey species, aquatic invertebrates being the most abundant prey items. However, brown trout also feed on other taxa such as terrestrial invertebrates (e.g. Hymenoptera) or other fish.[16] Moreover, in brown trout, as in many other fish species, a change in the diet composition normally occurs during the life of the fish,[17] and piscivorous behaviour is most frequent in large brown trout.[18] These shifts in the diet during fish lifecycle transitions may be accompanied by a marked reduction in intraspecific competition in the fish population, facilitating the partitioning of resources.[19][20]

First feeding of newly emerged fry is very important for brown trout survival in this phase of the lifecycle, and first feeding can occur even prior to emergence.[21][22] Fry start to feed before complete yolk absorption and the diet composition of newly emerged brown trout is composed of small prey such as chironomid larvae or baetid nymphs.[23]

Stocking, farming and non-native brown trout

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Brown trout (S. t. fario) in a Faroese stamp issued in 1994

The species has been widely introduced for sport fishing into North America, South America, Australia, New Zealand, and many other countries, including Bhutan, where they are the focus of a specialised fly fishery. First planting in the United States occurred April 11, 1884, into the Baldwin River, one mile east of Baldwin, MI.[24] Brown trout have had serious negative impacts on upland native fish species in some of the countries where they have been introduced, particularly Australia. Because of the trout's importance as a food and game fish, it has been artificially propagated and stocked in many places in its range, and fully natural populations (uncontaminated by allopatric genomes) probably exist only in isolated places, for example in Corsica or in high alpine valleys on the European mainland.

Farming of brown trout has included the production of infertile triploid fish by increasing the water temperature just after fertilisation of eggs, or more reliably, by a process known as pressure shocking. Triploids are favoured by anglers because they grow faster and larger than diploid trout. Proponents of stocking triploids argue, because they are infertile, they can be introduced into an environment that contains wild brown trout without the negative effects of cross-breeding. However, stocking triploids may damage wild stocks in other ways. Triploids certainly compete with diploid fish for food, space, and other resources. They could also be more aggressive than diploid fish and they may disturb spawning behaviour.

Angling

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Frontis and title page from The Fly-fisher's Entomology, 1849, by Alfred Ronalds, showing a brown trout and a grayling

The brown trout has been a popular quarry of European anglers for centuries. It was first mentioned in angling literature as "fish with speckled skins" by Roman author AElian (circa 200 AD) in On the Nature of Animals. This work is credited with describing the first instance of fly fishing for trout, the trout being the brown trout found in Macedonia.[25] The Treatyse of Fysshynge with an Angle (1496) by Dame Juliana Berners, O.S.B is considered a foundational work in the history of recreational fishing, especially fly fishing. One of the most prominent fish described in the work is the brown trout of English rivers and streams:

The trout, because he is a right dainty fish and also a right fervent biter, we shall speak of next. He is in season from March until Michaelmas. He is on clean gravel bottom and in a stream.

— Treatyse of Fysshynge with an Angle (1496)[26]

The renowned The Compleat Angler (1653) by Izaak Walton is replete with advice on "the trout":

The Trout is a fish highly valued, both in this and foreign nations. He may be justly said, as the old poet said of wine, and we English say of venison, to be a generous fish: a fish that is so like the buck, that he also has his seasons; for it is observed, that he comes in and goes out of season with the stag and buck. Gesner says, his name is of a German offspring; and says he is a fish that feeds clean and purely, in the swiftest streams, and on the hardest gravel; and that he may justly contend with all fresh water fish, as the Mullet may with all sea fish, for precedency and daintiness of taste; and that being in right season, the most dainty palates have allowed precedency to him.

— The Compleat Angler, (1653)[27]

Throughout the 17th, 18th, and 19th centuries, angling authors, mostly British, some French, and later American, writing about trout fishing were writing about fishing for brown trout. Once brown trout were introduced into the U.S. in the 1880s, they became a major subject of American angling literature. In 1889, Frederic M. Halford, a British angler, author published Dry-Fly Fishing in Theory and Practice, a seminal work codifying a half century of evolution of fly fishing with floating flies for brown trout. In the late 19th century, American angler and writer Theodore Gordon, often called the "Father of American Dry Fly Fishing" perfected dry-fly techniques for the newly arrived, but difficult-to-catch brown trout in Catskill rivers such as the Beaverkill and Neversink Rivers.[28] In the early 20th century, British angler and author G. E. M. Skues pioneered nymphing techniques for brown trout on English chalk streams. His Minor Tactics of the Chalk Stream (1910) began a revolution in fly fishing techniques for trout.[29] In 1917, Scottish author Hamish Stuart published the first comprehensive text, The Book of The Sea Trout, specifically addressing angling techniques for the anadromous forms of brown trout.[30]

Photo of brown trout and fly rod on river bank
Firehole river brown trout

Introductions of brown trout into the American West created new angling opportunities, none so successful from an angling perspective as was the introduction of browns into the upper Firehole River in Yellowstone National Park in 1890.[31] One of the earliest accounts of trout fishing in the park is from Mary Trowbridge Townsend's 1897 article in Outing Magazine "A Woman's Trout Fishing in Yellowstone Park" in which she talks about catching the von Behr trout in the river:

Long dashes down stream taxed my unsteady footing; the sharp click and whirr of the reel resounded in desperate efforts to hold him somewhat in check; another headlong dash, then a vicious bulldog shake of the head as he sawed back and forth across the rocks. Every wile inherited from generations of wily ancestors was tried until, in a moment of exhaustion, the net was slipped under him. Wading ashore with my prize, I had barely time to notice his size—a good four-pounder, and unusual markings, large yellow spots encircled by black, with great brilliancy of iridescent color—when back he flopped into the water and was gone. However, I took afterward several of the same variety, known in the Park as the Von Baer [sic] trout, and which I have since found to be the Salmo fario, the veritable trout of Izaak Walton.

— Outing Magazine, (1897)[32]

Within the US, brown trout introductions have created self-sustaining fisheries throughout the country. Many are considered "world-class" such as in the Great Lakes and in several Arkansas tailwaters.[33] Outside the U.S. and outside its native range in Europe, introduced brown trout have created "world-class" fisheries in New Zealand,[34] Patagonia,[35] and the Falklands.[36]

References

  1. ^ Freyhof, J. (2012). "Salmo trutta". IUCN Red List of Threatened Species. 2012. Retrieved 14 August 2012.old-form url
  2. ^ "Synonyms of Salmo trutta Linnaeus, 1758". Fishbase.org. Retrieved 2014-02-22.
  3. ^ Derwent Publications, Thesaurus of Agricultural Organisms, Vol. 1, London: Chapman and Hall, 1990, p. 1058.
  4. ^ E. Brown, World Fish Farming: Cultivation and Economics, Connecticut: AVI, 1983, p. 93.
  5. ^ "Trout Science". www.troutlet.com.
  6. ^ Lack of genetic differentiation between anadromous and resident sympatric brown trout (Salmo trutta) in a Normandy population. Archived 2007-05-18 at the Wayback Machine. In Aquatic Living Resources, Volume 18, N° 1, January–March 2005. Pages 65–69.
  7. ^ Behnke, Robert J.; Williams, Ted (2007). "Brown Trout-Winter 1986". About Trout: The Best of Robert J. Behnke from Trout Magazine. Guilford, CT: Globe Pequot. p. 45. ISBN 978-1-59921-203-6.
  8. ^ a b c d Behnke, Robert J.; Williams, Ted (2007). "Brown Trout-Winter 1986". About Trout: The Best of Robert J. Behnke from Trout Magazine. Guilford, CT: Globe Pequot. pp. 45–50. ISBN 978-1-59921-203-6.
  9. ^ "Global Invasive Species Database-Salmo trutta-Distribution". Invasive Species Specialist Group (ISSG) of the IUCN Species Survival Commission. Retrieved 2014-02-01.
  10. ^ a b c Heacox, Cecil E. (1974). "Back Cast". The Complete Brown Trout. New York: Winchester Press. pp. 7–23. ISBN 0-87691-129-7.
  11. ^ Newton, Chris (2013). "The Trout in India". The Trout's Tale – The Fish That Conquered an Empire. Ellesmere, Shropshire: Medlar Press. pp. 79–95. ISBN 978-1-907110-44-3.
  12. ^ "Brown Trout". www.flr.gov.nl.ca.
  13. ^ Newton, Chris (2013). "The Monsters of Kerguelen". The Trout's Tale – The Fish That Conquered an Empire. Ellesmere, Shropshire: Medlar Press. pp. 161–170. ISBN 978-1-907110-44-3.
  14. ^ "Climate Change and Freshwater". 11 February 2009 Archived February 11, 2011, at the Wayback Machine.
  15. ^ Splendiani, Andrea; Fioravanti, Tatiana; Giovannotti, Massimo; Negri, Alessandra; Ruggeri, Paolo; Olivieri, Luigi; Nisi Cerioni, Paola; Lorenzoni, Massimo; Caputo Barucchi, Vincenzo; Consuegra, Sofia (22 June 2016). "The Effects of Paleoclimatic Events on Mediterranean Trout: Preliminary Evidences from Ancient DNA". PLOS ONE. 11 (6): e0157975. Bibcode:2016PLoSO..1157975S. doi:10.1371/journal.pone.0157975. PMC 4917132. PMID 27331397.
  16. ^ Sánchez-Hernández, J.; Cobo, F. (2012). "Summer differences in behavioural feeding habits and use of feeding habitat among brown trout (Pisces) age classes in a temperate area". Italian Journal of Zoology. 79 (3): 468–478. doi:10.1080/11250003.2012.670274.
  17. ^ Sánchez-Hernández, J., Servia, M.J., Vieira-Lanero, R. & Cobo F. (2013). Ontogenetic dietary shifts in a predatory freshwater fish species: the brown trout as an example of a dynamic fish species. In: New Advances and Contributions to Fish Biology, Hakan Türker (Ed.). ISBN 978-953-51-0909-9, InTech, Croatia, 271–298 pp.
  18. ^ Jensen, H.; Kiljunen, M.; Amundsen, P-A. (2012). "Dietary ontogeny and niche shift to piscivory in lacustrine brown trout Salmo trutta revealed by stomach content and stable isotope analyses". Journal of Fish Biology. 80 (7): 2448–2462. doi:10.1111/j.1095-8649.2012.03294.x. PMID 22650427.
  19. ^ Elliott, J.M. (1967). "The food of trout (Salmo trutta) in a Dartmoor stream". Journal of Applied Ecology. 4 (1): 59–71. doi:10.2307/2401409. JSTOR 2401409.
  20. ^ Amundsen, P-A.; Bøhn, T.; Popova, O.A.; Staldvik, F.J.; Reshetnikov, Y.S.; Kashulin, N.; Lukin, A. (2003). "Ontogenetic niche shifts and resource partitioning in a subarctic piscivore fish guild". Hydrobiologia. 497 (1–3): 109–119. doi:10.1023/A:1025465705717. hdl:10037/19124. S2CID 23002949.
  21. ^ Zimmerman, C.E.; Mosegaard, H. (1992). "Initial feeding in migratory brown trout (Salmo trutta L.) alevins". Journal of Fish Biology. 40 (4): 647–650. doi:10.1111/j.1095-8649.1992.tb02612.x.
  22. ^ Skoglund, H.; Barlaup, B.T. (2006). "Feeding pattern and diet of first feeding brown trout fry under natural conditions". Journal of Fish Biology. 68 (2): 507–521. doi:10.1111/j.0022-1112.2006.00938.x.
  23. ^ Sánchez-Hernández, J.; Vieira-Lanero, R.; Servia, M.J.; Cobo, F. (2011a). "First feeding diet of young brown trout fry in a temperate area: disentangling constrains and food selection". Hydrobiologia. 663 (1): 109–119. doi:10.1007/s10750-010-0582-3. S2CID 23870995.
  24. ^ Brown Trout, Salmo trutta Archived 2010-06-07 at the Wayback Machine Sea Grant. Retrieved 14 February 2010.
  25. ^ Herd, Andrew Dr (2001). "Beginnings". The Fly. Ellesmere, Shropshire: Medlar Press. pp. 19–74. ISBN 1-899600-19-1.
  26. ^ Andrew Herd. "Translation-Treatyse of Fysshynge with an Angle Fishes". Flyfishinghistory.com. Archived from the original on 2014-01-27. Retrieved 2014-02-02.
  27. ^ Walton, Izaak (1653). The Compleat Angler. London.
  28. ^ McDonald, John (1972). "Gordan and American Fly-fishing". Quill Gordon. New York: Alfred A. Knopf. pp. 34–44. ISBN 0394469895.
  29. ^ Gingrich, Arnold (1974). The Fishing In Print-A Guided Tour Through Five Centuries of Angling Literature. New York: Winchester Press. pp. 224–225.
  30. ^ Newton, Chris (2013). "Two Fish in One". The Trout's Tale – The Fish That Conquered an Empire. Ellesmere, Shropshire: Medlar Press. pp. 31–36. ISBN 978-1-907110-44-3.
  31. ^ Franke, Mary Ann (Fall 1996). "A Grand Experiment—100 Years of Fisheries Management in Yellowstone: Part I" (PDF). Yellowstone Science. 4 (4).
  32. ^ Townsend, Mary Trowbridge (May 2, 1897), "A Woman's Trout Fishing in Yellowstone Park", Outing Magazine, XXX (2): 163
  33. ^ Price, Steve. Arkansas Monster Browns. Field and Stream. Retrieved 2014-02-22.
  34. ^ McGinley, Morgan (January 26, 2010). "A Long Road to World-Class Fly Fishing in New Zealand". New York Times. Retrieved 2014-02-22.
  35. ^ Kaminsky, Peter (February 11, 2006). "At the End of the World, the Fish Stories Are True". New York Times. Retrieved 2014-02-22.
  36. ^ Newton, Chris (2013). "Falklands' Silver". The Trout's Tale – The Fish That Conquered an Empire. Ellesmere, Shropshire: Medlar Press. pp. 149–159. ISBN 978-1-907110-44-3. The Chartres produces some great fishing ...When he was reunited with the party a few hours later, he had taken 15 sea trout from 7 lbs to 14 1/2 lbs – world-class fishing by any yardstick
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Brown trout: Brief Summary

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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 streams, but sometimes in larger rivers. Anadromous and non-anadromous morphs coexisting in the same river appear genetically identical. What determines whether or not they migrate remains unknown.

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Salmo trutta fario

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Salmo trutta fario, sometimes called the river trout,[2] 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, which also includes sea trout (Salmo trutta trutta) and a lacustrine trout (Salmo trutta lacustris). Depending on the supply of food, river trout measure 20 to 80 cm (0.7–2.6 ft) in length; exceptionally they may be up to 1 m (3.3 ft) long and weigh up to over 13 kg (29 lb). Their back is olive-dark brown and silvery blue, red spots with light edges occur towards the belly, the belly itself is whitish yellow. River trout usually attain a weight of up to 2 kg (4.4 lb). They can live for up to 18 years.

Habitat

River trout live in fast flowing, oxygen-rich, cool clear waters with gravel or sandy riverbeds. They occur across almost all of Europe, from Portugal to the Volga, with the exception of Central Anatolia and the Caucasus regions. They are found as far north as Lapland. They do not occur in Greece or on the islands of Corsica, Sardinia and Sicily.

River trout are very faithful to their habitat (i.e. they live only at one spot and do not migrate), leaving it only to reproduce. Even after being disturbed they will return to their traditional sites. The adult river trout requires its own territory. During the day it is hidden in the shadows of the river bank, facing upstream.

Depending on size and habitat, they feed mainly on insects and insect larvae that live in water, small fish such as bullhead, small crustaceans, snails and other water animals. Cannibalism has also been frequently observed among river trout. They are fast swimming predators, but in rivers and streams they will usually take prey that is being driven past by the current.

Reproduction

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River trout in the "Subaqueous Vltava" exhibition, Prague

River trout spawn between October and January in the northern hemisphere and between May and June in the southern hemisphere. The fish uses rapid fanning of the tail and caudal fin on a rock riverbed to make several shallow pits, into which about 1,000 to 1,500 reddish eggs, four to five millimetre wide, are laid. The fish larvae emerge after two to four months.

The river trout has a special significances as a host fish for the glochidia of the freshwater pearl mussel.

Other forms

Because trout live in habitats with fixed boundaries, in addition to the river trout, Salmo trutta fario, there are various other subspecies of Salmo trutta. See Species of Trout.

Hybrids

The tiger trout (Salmo trutta fario × Salvelinus fontinalis) is a genetic cross between a river trout and a brook trout. It gets its name from its characteristic golden yellow markings. Tiger trout are sterile, despite male and female may be distinguished by their external markings. The female tiger trout does not develop any gonads. By contrast, male tiger trout develop testicles as well as secondary sex features such as kypes, humps, darker and thicker skin and a lighter fillet colouring during the spawning season.

Fishing

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Well camouflaged river trout in a small stream
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River trout caught with the help of a fly

In the past, European waterbodies were heavily and artificially stocked with rainbow trout, a native of America that grows more quickly and is less demanding of water quality. It is disputed whether this threatens the river trout. Today, it is bred in fishponds with almost the same rate of success as the rainbow trout, for food and for restocking rivers. To protect native species of fish, the stocking of rivers with non-native species has been restricted for several years.

River trout makes an excellent fish dish.

Angling

River trout is very popular with anglers. It is frequently fished using artificial lures. Angling with natural lures (worms, maggots, grasshoppers) is discouraged in most rivers because it is difficult to throw those trout back that are below the minimum landing size uninjured, when they have ingested this food so quickly and deeply.

Fly rods are used to catch river trout. Medium-sized, wet and dry flies are thrown into streams with a rod of AFTMA Class 4-6 and are intended to mimic an emerging or egg-laying insect. A spinning rod can also be used in some waters. For this purpose, a light spinning rod and various artificial lures, such as spoon lures and spinners are used. In using wobblers and rubber fish care should be taken because they are banned on some waterbodies or may only be used with restrictions.

Research use

The fish has been used as a bio-indicator species in freshwater systems due to their sensitive nature. They are a well-established ‘model organism’ in aquatic toxicology research, especially for heavy metal bioaccumulation.[3]

References

  1. ^ Freyhof, J. (2012). "Salmo trutta". IUCN Red List of Threatened Species. 2012. Retrieved 14 August 2012.old-form url
  2. ^ John Gunn, editor (2004), Encyclopedia of Caves and Karst Science, New York/London: Taylor & Francis, p. 1278. ISBN 1-57958-399-7.
  3. ^ Dvorak, Petr; Roy, Koushik; Andreji, Jaroslav; Liskova, Zuzana Dvorakova; Mraz, Jan (March 2020). "Vulnerability assessment of wild fish population to heavy metals in military training area: Synthesis of a framework with example from Czech Republic". Ecological Indicators. 110: 105920. doi:10.1016/j.ecolind.2019.105920.
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Salmo trutta fario: Brief Summary

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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, which also includes sea trout (Salmo trutta trutta) and a lacustrine trout (Salmo trutta lacustris). Depending on the supply of food, river trout measure 20 to 80 cm (0.7–2.6 ft) in length; exceptionally they may be up to 1 m (3.3 ft) long and weigh up to over 13 kg (29 lb). Their back is olive-dark brown and silvery blue, red spots with light edges occur towards the belly, the belly itself is whitish yellow. River trout usually attain a weight of up to 2 kg (4.4 lb). They can live for up to 18 years.

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Sea trout

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Sea trout is the common name usually applied to anadromous (or sea-run) forms of brown trout (Salmo trutta), and is often referred to as Salmo trutta morpha trutta. Other names for anadromous brown trout are sewin (Wales), peel or peal (southwest England), mort (northwest England), finnock (Scotland), white trout (Ireland) and salmon trout (culinary).[2] The term sea trout is also used to describe other anadromous salmonidscoho salmon (Oncorhynchus kisutch), brook trout (Salvelinus fontinalis), Arctic char (Salvelinus alpinus alpinus), cutthroat trout (Oncorhynchus clarkii) and Dolly Varden (Salvenlinus malma).[3] Even some non-salmonid species are also commonly known as sea trout—Northern pikeminnow (Ptychocheilus oregonensis) and members of the weakfish family (Cynoscion).[3]

Jumping sea trout

Range

Anadromous brown trout are widely distributed in Europe along the Atlantic and Baltic coasts, the United Kingdom and the coasts of Iceland. They do not occur in the Mediterranean Sea but are found in the Black and Caspian Seas and as far north as the Barents and Kara Seas in the Arctic Ocean.[4][5] Brown trout introduced into freshwater habitats in Tasmania, Victoria, New Zealand, Falkland Islands, Kerguelen Islands, Chile and Argentina have established anadromous populations when there was suitable access to saltwater.[4] Anadromous behavior has been reported in the Columbia river and its tributaries in the U.S. and in Canadian rivers on both the Pacific and Atlantic coasts.[6]

Taxonomy

As treated here, the anadromous sea trout Salmo trutta morpha trutta is not taxonomically distinct from the freshwater-resident forms of the brown trout, i.e. the lacustrine S. t. morpha lacustris and the riverine S. t. morpha fario, although previously they have been considered different subspecies or even species. They represent ecological forms with different migration behaviour. Originally the name Salmo trutta was used to refer specifically to the anadromous or sea-run forms of brown trout.[7] Early angling literature often referred to sea trout as white trout or bull trout.[8]

Description

Anadromous brown trout are a silvery color with faint black spots. However, once they return to freshwater they quickly take on the normal coloration of resident brown trout in preparation for spawning. Sea trout kelts (post spawn) return to their silvery stage as they migrate back to saltwater.[9] Adult brown trout are between 35 to 60 centimetres (14 to 24 in) long, and can weigh from 0.5 to 2.4 kilograms (1.1 to 5.3 lb). Breeding males will develop a hook-like, upward-facing protrusion on the lower jaw called a kype. In freshwater the top of the trout is an olive color with brown and black spots with the ventral side being tan to yellow. The sides have many orange and red spots ringed with a light blue.[10]

Life cycle

Their average length is 60 cm, but they can grow up to 130 cm in length and weigh up to 20 kg under favourable habitat conditions.

Their most striking feature is the long, elongated, torpedo-shaped body. They have silver grey sides and grey-green backs. The belly is white. Like all trout species the sea trout has an adipose fin.

Sea trout feed mainly on fish, small crabs, shrimps and prawns.

It is an anadromous, migratory fish, which closely resembles the Atlantic salmon in its form and lifestyle. In the sea, it makes long journeys and also swims upstream into small rivers in order to spawn. Spawning occurs in winter on gravelly river beds in the grayling zone to the barbel zone. Their eggs are laid in troughs or redds. The young fish remain in freshwater for one to five years and then make their way to the sea. The "inner clock" signals to the fish when they need to make their return journey to the sea. During this migration, they can cover up to 40 km per day.

Fish that are ready for spawning are usually lean and have to eat a lot of food in order to increase their energy levels as quickly as possible. After completion of the spawning process, the fish return to the sea. The mass mortality after spawning that is common in some species of salmon is not usual for brown trout. Once back in the sea, the fish regain their weight and lose their brown spawning colouring.

The surviving young of sea trout will generally migrate back to the sea, to feed in estuaries and coastal waters. However it is also known that adult brown trout, which may have spent some years entirely in a river, can for whatever reason decide to migrate to sea, to return next year as a much larger (sea) trout, with beautiful silver colouration.

Threats

In many rivers of Central Europe, the sea trout have been extirpated because hydropower plants prevent spawning migration. In addition, many spawning grounds have disappeared due to the backflooding of rivers. In more recent times, sea trout have succeeded in re-establishing themselves in some lakes and rivers through the introduction of fish ladders and bypass channels around hydropower plants. In this way spawning migration has been enabled again, albeit in a limited way.

Angling

Sea trout are popular with anglers and as food. The close season lasts at least three months depending on river authority regulations. Like salmon, sea trout are protected by law in the Rhine river system and in most German rivers (except some northern German rivers) all year-round.

In the coastal waters of Schleswig-Holstein, sea trout is protected from 1 October to 31 December. This applies only for fish in spawning colour (brown), the silver coloured fish may continue to be caught. In most estuaries angling is completely prohibited in a protected area of 200 metres around the river mouth during this time.

In the coastal waters of Mecklenburg-Vorpommern, there is a general prohibition on fishing for sea trout from 15 September to 14 December. This applies both to fishermen and anglers.

In Germany, the term Absteiger is used by anglers to describe a sea trout after spawning. The removal of absteigers is a controversial topic among anglers. Most anglers refuse to take sea trout that have spawned because their meat is inferior and dry.

In North Wales the rivers Clwyd, Elwy and (to a lesser extent) Aled have runs of migratory trout, otherwise known as sea trout or, locally, sewin . Sewin generally refers to smaller sea trout up to around 30 – 40 cm in length. Fishing (angling) for sea trout is usually carried out at night using fly fishing techniques, but only when the rivers are running clear. Sea trout are very easily "spooked" by bankside disturbance and during daylight hours tend to be tucked up under the banks and submerged tree roots, and therefore very hard to catch. At night they feel more confident to come out into the main river flow and can often be seen "running" (migrating upstream) in the shallow runs during the months of May to November. When the rivers are flowing coloured in a spate following heavy rain, it is possible to catch sea trout during the day with artificial lures or spinners. The fishing season for sea trout in the Clwyd catchment is from March 20 to October 17 inclusive. Many fly fishermen would agree that night fishing for sea trout can be one of the most exciting forms of the sport as the fish can grow to more than 10 lbs (5 kg) in weight. The Rhyl and St Asaph Angling Association[11] controls 20 miles of river fishing on the rivers Clwyd, Elwy and Aled.

References

  1. ^ Freyhof, J. (2012). "Salmo trutta". IUCN Red List of Threatened Species. 2012. Retrieved 14 August 2012.old-form url
  2. ^ Everard, Mark. Britain's Freshwater Fishes. Princeton: PUP, 2013, p. 84.
  3. ^ a b "List of Common Names with sea trout". FishBase. Retrieved October 3, 2016.
  4. ^ a b "Trout Facts-Sea trout". Wild Trout Trust. Retrieved October 3, 2016.
  5. ^ Blglinière, Jean-Luc; Maisse, Gerard (1999). "Introduction:The Brown trout (Salmo trutta): its origins, distribution and economic and scientific significance". Biology and Ecology of the Brown and Sea Trout. Chichester, UK: Praxis Publishing. pp. 1–14. ISBN 978-1852331177.
  6. ^ Bisson, Peter A. (1986). "Occurrence of anadromous brown trout in two lower Columbia River tributaries" (PDF). North American Journal of Fisheries Management. 6 (2): 290–292. doi:10.1577/1548-8659(1986)6<290:OOABTI>2.0.CO;2.
  7. ^ Behnke, Robert J.; Williams, Ted (2007). "Brown Trout-Winter 1986". About Trout: The Best of Robert J. Behnke from Trout Magazine. Guilford, CT: Globe Pequot. p. 45. ISBN 978-1-59921-203-6.
  8. ^ Harry Cholmondeley - Pennell (1884). "White Trout Fishing". The modern practical angler: A Complete Guide to Fly-fishing, Bottom-fishing & Trolling. London: George Routledge and Sons. pp. 130–135.
  9. ^ "Sea trout recognition" (PDF). Wild Trout Trust. Retrieved October 3, 2016.
  10. ^ "Salmo trutta". Animal Diversity Web. Retrieved October 3, 2016.
  11. ^ Rhyl and St Asaph Angling Association

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Sea trout: Brief Summary

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Sea trout is the common name usually applied to anadromous (or sea-run) forms of brown trout (Salmo trutta), and is often referred to as Salmo trutta morpha trutta. Other names for anadromous brown trout are sewin (Wales), peel or peal (southwest England), mort (northwest England), finnock (Scotland), white trout (Ireland) and salmon trout (culinary). The term sea trout is also used to describe other anadromous salmonidscoho salmon (Oncorhynchus kisutch), brook trout (Salvelinus fontinalis), Arctic char (Salvelinus alpinus alpinus), cutthroat trout (Oncorhynchus clarkii) and Dolly Varden (Salvenlinus malma). Even some non-salmonid species are also commonly known as sea trout—Northern pikeminnow (Ptychocheilus oregonensis) and members of the weakfish family (Cynoscion).

Jumping sea trout
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Description

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Confined to cold, well-oxygenated upland waters although their tolerance limits are lower than those of rainbow trout. Favours large streams in the mountanous areas with adequate cover in the form of submerged rocks, undercut banks and overhanging vegetation (Ref. 6465). Mainly diurnal (Ref. 682). Marketed fresh and smoked; eaten fried, broiled, boiled, microwaved and baked (Ref. 9988).
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Froese, R. & D. Pauly (Editors). (2021). FishBase. World Wide Web electronic publication. version (02/2021). Hayes, K.; Sliwa, C.; Migus, S.; McEnnulty, F.; Dunstan, P.; Heritagearkes, P. (2005). National priority pests. Part II, Ranking of Australian marine pests. Australian Government Department of the Environment and Heritage: Parkes. ISBN 1 876996 80 3. 94 pp. Hayes, K.; Sliwa, C.; Migus, S.; McEnnulty, F.; Dunstan, P.; Heritagearkes, P. (2005). National priority pests. Part II, Ranking of Australian marine pests. Australian Government Department of the Environment and Heritage: Parkes. ISBN 1 876996 80 3. 94 pp. Hayes, K.; Sliwa, C.; Migus, S.; McEnnulty, F.; Dunstan, P.; Heritagearkes, P. (2005). National priority pests. Part II, Ranking of Australian marine pests. Australian Government Department of the Environment and Heritage: Parkes. ISBN 1 876996 80 3. 94 pp.
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Diet

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Feeds on insects, molluscs, crustaceans and small fish
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Nijssen, H.; de Groot, S.J. (1987). De vissen van Nederland: systematische indeling, historisch overzicht, het ontstaan van de viskweek, uitheemse vissoorten, determineersleutels, beschrijvingen, afbeeldingen, literatuur, van alle in Nederlandse wateren voor komende zee- en zoetwatervissoorten [Fishes of the Netherlands: systematic classification, historical overview, origins of fish culture, non-indigenous species, determination keys, descriptions, drawings, literature references on all marine and freshwater fish species living in Dutch waters]. KNNV Uitgeverij: Utrecht, The Netherlands. ISBN 90-5011-006-1. 224 pp. North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) Schwindt, E.; Carlton, J.; Orensanz, J.; Scarabino, F.; Bortolus, A. (2020). Past and future of the marine bioinvasions along the Southwestern Atlantic. <em>Aquatic Invasions.</em> 15(1): 11-29. Schwindt, E.; Carlton, J.; Orensanz, J.; Scarabino, F.; Bortolus, A. (2020). Past and future of the marine bioinvasions along the Southwestern Atlantic. <em>Aquatic Invasions.</em> 15(1): 11-29.
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Distribution

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Newfoundland to New Brunswick
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Nijssen, H.; de Groot, S.J. (1987). De vissen van Nederland: systematische indeling, historisch overzicht, het ontstaan van de viskweek, uitheemse vissoorten, determineersleutels, beschrijvingen, afbeeldingen, literatuur, van alle in Nederlandse wateren voor komende zee- en zoetwatervissoorten [Fishes of the Netherlands: systematic classification, historical overview, origins of fish culture, non-indigenous species, determination keys, descriptions, drawings, literature references on all marine and freshwater fish species living in Dutch waters]. KNNV Uitgeverij: Utrecht, The Netherlands. ISBN 90-5011-006-1. 224 pp. North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) Schwindt, E.; Carlton, J.; Orensanz, J.; Scarabino, F.; Bortolus, A. (2020). Past and future of the marine bioinvasions along the Southwestern Atlantic. <em>Aquatic Invasions.</em> 15(1): 11-29. Schwindt, E.; Carlton, J.; Orensanz, J.; Scarabino, F.; Bortolus, A. (2020). Past and future of the marine bioinvasions along the Southwestern Atlantic. <em>Aquatic Invasions.</em> 15(1): 11-29.
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Mary Kennedy [email]

Habitat

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Inhabit cold, well oxygenated streams, except from June to August when they migrate to sea.
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Nijssen, H.; de Groot, S.J. (1987). De vissen van Nederland: systematische indeling, historisch overzicht, het ontstaan van de viskweek, uitheemse vissoorten, determineersleutels, beschrijvingen, afbeeldingen, literatuur, van alle in Nederlandse wateren voor komende zee- en zoetwatervissoorten [Fishes of the Netherlands: systematic classification, historical overview, origins of fish culture, non-indigenous species, determination keys, descriptions, drawings, literature references on all marine and freshwater fish species living in Dutch waters]. KNNV Uitgeverij: Utrecht, The Netherlands. ISBN 90-5011-006-1. 224 pp. North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) Schwindt, E.; Carlton, J.; Orensanz, J.; Scarabino, F.; Bortolus, A. (2020). Past and future of the marine bioinvasions along the Southwestern Atlantic. <em>Aquatic Invasions.</em> 15(1): 11-29. Schwindt, E.; Carlton, J.; Orensanz, J.; Scarabino, F.; Bortolus, A. (2020). Past and future of the marine bioinvasions along the Southwestern Atlantic. <em>Aquatic Invasions.</em> 15(1): 11-29.
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Mary Kennedy [email]

Habitat

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nektonic
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Nijssen, H.; de Groot, S.J. (1987). De vissen van Nederland: systematische indeling, historisch overzicht, het ontstaan van de viskweek, uitheemse vissoorten, determineersleutels, beschrijvingen, afbeeldingen, literatuur, van alle in Nederlandse wateren voor komende zee- en zoetwatervissoorten [Fishes of the Netherlands: systematic classification, historical overview, origins of fish culture, non-indigenous species, determination keys, descriptions, drawings, literature references on all marine and freshwater fish species living in Dutch waters]. KNNV Uitgeverij: Utrecht, The Netherlands. ISBN 90-5011-006-1. 224 pp. North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) Schwindt, E.; Carlton, J.; Orensanz, J.; Scarabino, F.; Bortolus, A. (2020). Past and future of the marine bioinvasions along the Southwestern Atlantic. <em>Aquatic Invasions.</em> 15(1): 11-29. Schwindt, E.; Carlton, J.; Orensanz, J.; Scarabino, F.; Bortolus, A. (2020). Past and future of the marine bioinvasions along the Southwestern Atlantic. <em>Aquatic Invasions.</em> 15(1): 11-29.
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Mary Kennedy [email]

Introduction

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This species has been introduced or released in Dutch waters.
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Nijssen, H.; de Groot, S.J. (1987). De vissen van Nederland: systematische indeling, historisch overzicht, het ontstaan van de viskweek, uitheemse vissoorten, determineersleutels, beschrijvingen, afbeeldingen, literatuur, van alle in Nederlandse wateren voor komende zee- en zoetwatervissoorten [Fishes of the Netherlands: systematic classification, historical overview, origins of fish culture, non-indigenous species, determination keys, descriptions, drawings, literature references on all marine and freshwater fish species living in Dutch waters]. KNNV Uitgeverij: Utrecht, The Netherlands. ISBN 90-5011-006-1. 224 pp. North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) Schwindt, E.; Carlton, J.; Orensanz, J.; Scarabino, F.; Bortolus, A. (2020). Past and future of the marine bioinvasions along the Southwestern Atlantic. <em>Aquatic Invasions.</em> 15(1): 11-29. Schwindt, E.; Carlton, J.; Orensanz, J.; Scarabino, F.; Bortolus, A. (2020). Past and future of the marine bioinvasions along the Southwestern Atlantic. <em>Aquatic Invasions.</em> 15(1): 11-29.
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[email]