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Overview

Brief Summary

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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Comprehensive Description

Biology

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).
  • Svetovidov, A.N. 1984 Salmonidae. p. 373-385. In P.J.P. Whitehead, M.-L. Bauchot, J.-C. Hureau, J. Nielsen and E. Tortonese (eds.) Fishes of the north-eastern Atlantic and the Mediterranean. UNESCO, Paris. vol. 1. (Ref. 4779)
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Distribution

Global Range: Native to Europe and western Asia. Introduced and established throughout much of U.S. and southern Canada; locally common.

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Range Description

Atlantic, North, White and Baltic Sea basins, from Spain to Chosha Bay (Russia). Present in Iceland and in northernmost rivers of Great Britain and Scandinavia. In Rhône drainage, native only to Lake Geneva basin, which it entered after last glaciation. Native to upper Danube and Volga drainages. Introduced throughout Europe, North and South America, southern and montane eastern Africa, Pakistan, India, Nepal, Japan, New Zealand and Australia.
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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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Europe and Asia: Atlantic, North, White and Baltic Sea basins, from Spain to Chosha Bay (Russia). Found in Iceland and northernmost rivers of Great Britain and Scandinavia. In Rhône drainage, native only to Lake Geneva basin, which it entered after last glaciation. Native to upper Danube and Volga drainages. Introduced widely. Several countries report adverse ecological impact after introduction.
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occurs (regularly, as a native taxon) in multiple nations

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National Distribution

Canada

Origin: Exotic

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Exotic

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

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Eastern North Atlantic, Baltic Sea, North Sea, Mediterranean Sea, Black Sea, Caspian Sea, Europe and western Asia, introduced widely elsewhere.
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Physical Description

Morphology

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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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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Size

Length: 103 cm

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Max. size

140 cm SL (male/unsexed; (Ref. 682)); max. published weight: 50.0 kg (Ref. 682); max. reported age: 38 years (Ref. 32682)
  • Svalastog, D. 1991 A note on maximum age of brown trout, Salmo trutta L. J. Fish Biol. 38(6):967-968. (Ref. 32682)
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Diagnostic Description

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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Ecology

Habitat

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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Habitat and Ecology

Habitat and Ecology
Habitat:
Cold streams, rivers and lakes. Spawns in rivers and streams with swift water. Lacustrine populations migrate to tributaries and lake outlets, rarely spawning on stone, wave-washed lake shores. Spawning sites usually characterised by downward movement of water into gravel. Sea and lake trouts forage in pelagic and littoral habitats, sea trouts mostly close to coast, not very far from estuary of natal river.

Biology:
Anadromous, lacustrine and resident ecotypes. Spawns in couples between late October and March, usually in November-December. Females select spawning sites and deposit the redd. Males guard and defend females against other males. Eggs are covered with gravel by female. Both sexes usually survive spawning and anadromous trout migrate back to sea or lake in autumn or overwinter in rivers and migrate in spring (5-70 % repetitive spawners in Norway). Sea trouts generally feed in freshwater. Eggs are covered with 3-30 cm of gravel. Redd depth is positively related to female's size. Eggs in deep redds are less vulnerable to spates and wash-outs and more vulnerable to low oxygen concentrations and pollution. Fry usually emerge from gravel between March (Spain) and July (Finland). Parrs and resident trouts are territorial, feeding on drifting and benthic invertebrates. Success in finding and defending a feeding territory is positively correlated to size of fry and to mother's size. Being large is clearly advantageous at this stage of life cycle. Resident trouts usually spawn for the first time at 2-3 years and spawn 2-3 seasons. Smoltification usually complete at 2-3 years and 120-220 mm SL, but up to seven year old smolts are reported. Mean smolt age increases with latitude. All juveniles seem to have the genetic ability to smoltify and migrate; in some small, summer-dry streams all migrate. In other streams, almost none seem to migrate. Factors triggering the 'decision' of an individual to smoltify or not are not well understood. If migration is impossible, smolts may interrupt migration and become resident again. In most rivers, a greater proportion of females than males seems to migrate, apparently a response to a greater need for reproductive energy. Therefore, sex ratio is usually skewed towards females in smolts. Large anadromous females may spawn with small resident males (the reverse is not reported but is expected to be possible, too). Smolts start to migrate downstream in April-May when temperature increases from low winter level, reaching beyond 5-11°C; migration peaks at rising water levels with increased turbidity.

There is a great variability in life history details of lacustrine populations. In some lakes, fry may migrate to the lake and at least males may spawn for the first time at two years. In other lakes, parrs smoltify after spending 1-3 years in spawning streams and males feed 4-6, females 5-8 years before first reproduction. At sea and in lakes, trouts feed on small fish and large crustaceans. In lakes, aquatic and terrestrial insects may form an important part of the diet. After at least 18 month at sea, sea trouts start to return to rivers to spawn. The pattern and timing of upstream migrations depends on particular river, sex and age. Homing accuracy is not as high as in S. salar. After spending one summer at sea, whitling start to migrate in July-September to lower reaches of rivers to overwinter or mature and migrate to spawning sites. Anadromous adults migrate in May and enter rivers until late October. Most maturing whitlings are males and the proportion of whitlings might be up to 30 % among spawners. Whitlings usually sneak in to spawn in redds of large couples, as resident males do, too. Large males attack, injure and often kill sneakers. After one spawning season as whitling or resident male, individual trouts may spawn again as large sea trout. The factors triggering the 'choice' to reproduce as whitling or as large male seems to be related to body size of young parrs since larger parrs more frequently develop the whitling tactic and smaller parrs the large male tactic. During upriver migrations, the silvery colour evolves into a dark breeding colour, the skull of males enlarges and the lower jaw develops a kype. Sometimes hybridises with S. salar.

Systems
  • Freshwater
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Habitat Type: Freshwater

Comments: Mostly in cold, medium to high gradient streams, but lake and sea-run populations also exist. Tends to occupy deeper, lower velocity, and warmer waters than other species of trout (Sublette et al. 1990). Does best where dissolved oxygen concentration is at least 9 ppm and, in small streams, where canopy shade is 50-75% at midday (Sublette et al. 1990). Some migratory populations spend first 2 years in river, 1-2 years in lake, then return to river to spawn at 3-4 years. Spawns in waters ranging from large streams to small spring- fed tributaries; in shallow gravelly headwaters, rocky lake margins, or sometimes over sand or hard clay if no gravel available. Spawns in natal stream. Fry occupy quiet waters along shorelines or in shelter of objects that deflect flows (Sublette et al. 1990).

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Environment

pelagic-neritic; anadromous (Ref. 51243); freshwater; brackish; marine; depth range 0 - ? m, usually ? - 10 m
  • Riede, K. 2004 Global register of migratory species - from global to regional scales. Final Report of the R&D-Projekt 808 05 081. Federal Agency for Nature Conservation, Bonn, Germany. 329 p. (Ref. 51243)
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Depth range based on 327 specimens in 2 taxa.
Water temperature and chemistry ranges based on 19 samples.

Environmental ranges
  Depth range (m): -9 - 92
  Temperature range (°C): 4.995 - 10.817
  Nitrate (umol/L): 1.687 - 6.728
  Salinity (PPS): 9.183 - 34.886
  Oxygen (ml/l): 2.247 - 7.708
  Phosphate (umol/l): 0.389 - 1.719
  Silicate (umol/l): 2.022 - 48.967

Graphical representation

Depth range (m): -9 - 92

Temperature range (°C): 4.995 - 10.817

Nitrate (umol/L): 1.687 - 6.728

Salinity (PPS): 9.183 - 34.886

Oxygen (ml/l): 2.247 - 7.708

Phosphate (umol/l): 0.389 - 1.719

Silicate (umol/l): 2.022 - 48.967
 
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.

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Migration

Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.

Locally Migrant: Yes. At least some populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: No. No populations of this species make annual migrations of over 200 km.

Migrates between lakes and spawning streams or between sea and spawning streams in some areas (Scott and Crossman 1973).

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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.
  • Riede, K. 2004 Global register of migratory species - from global to regional scales. Final Report of the R&D-Projekt 808 05 081. Federal Agency for Nature Conservation, Bonn, Germany. 329 p. (Ref. 51243)
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Trophic Strategy

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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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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Comments: Eats aquatic and terrestrial insects and their larvae, crustaceans (especially crayfish), molluscs, fishes, and other animals. In streams, young feed mainly on aquatic and terrestrial drift invertebrates; in lakes, they feed on zooplankton and benthic invertebrates (Sublette et al. 1990). Large adults feed on fishes, crayfish, and other benthic invertebrates.

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Associations

In Great Britain and/or Ireland:
Animal / parasite / ectoparasite
Argulus foliaceus ectoparasitises skin of Salmo trutta

Animal / parasite / endoparasite
fluke of Crepidostomum faronis endoparasitises hind gut of Salmo trutta

Animal / parasite / endoparasite
fluke of Crepidostomum metoecus endoparasitises intestine of Salmo trutta

Animal / parasite / endoparasite
Cryptobia truttae endoparasitises blood of Salmo trutta

Animal / parasite / endoparasite
tapeworm of Cystidicola farionis endoparasitises swim bladder of Salmo trutta

Animal / parasite
tapeworm of Cystidicoloides tenuissima parasitises Salmo trutta

Animal / parasite / endoparasite
Diphyllobothrium dendriticum endoparasitises body cavity of Salmo trutta

Animal / parasite / endoparasite
metacaria (diplostomula) of Diplostomum gasterostei endoparasitises eye (humour) of Salmo trutta

Animal / parasite / endoparasite
metacaria (diplostomula) of Diplostomum spathaceum endoparasitises eye (lens) of Salmo trutta

Animal / parasite / endoparasite
Echinorhynchus truttae endoparasitises Salmo trutta

Animal / parasite / endoparasite
tapeworm of Eubothrium crassum endoparasitises intestine of Salmo trutta

Animal / parasite / endoparasite
Neoechinorhynchus rutili endoparasitises intestine of Salmo trutta

Animal / pathogen
colony of Saprolegnia parasitica infects epidermis of Salmo trutta

Animal / parasite / endoparasite
metacaria (diplostomula) of Tyrodelphys clavata endoparasitises vitreous humour of Salmo trutta

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Known predators

Salmo trutta (Salmo trutta (N=3)) is prey of:
Lutra lutra
Phalacrocorax carbo
Ardea cinerea
Larus argentatus

Based on studies in:
Scotland (Estuarine)

This list may not be complete but is based on published studies.
  • Hall SJ, Raffaelli D (1991) Food-web patterns: lessons from a species-rich web. J Anim Ecol 60:823–842
  • Huxham M, Beany S, Raffaelli D (1996) Do parasites reduce the chances of triangulation in a real food web? Oikos 76:284–300
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Known prey organisms

Salmo trutta (Salmo trutta (N=3)) preys on:
Insecta
zoobenthos
Cyclops
Simulium
Crangon crangon
Nereis diversicolor
Copepoda
Balanus balanoides
Neomysis integer
Corophium volutator
Gammarus
Jaera albifrons
Hydrobia ulvae
Lepomis macrochirus
Terrestrial invertebrates
Plant material
Costachorema xanthoptera
Deleatidium lilli
Megaleptoperla diminuta
Oeconesus
Oligochaeta
Paracalliope fluviatalus
Polyplectropus puerilis
Stenoperla prasinia
Zelandoperla agnetis
Paranephrops zealandicus
detritus
Amphipoda
Aoteapsyche
Aphrophila noevaezelandiae
Austrosimulium australense
Maoridiamesea
Naonella
Coloburiscus humeralis
Deleatidium
Hudsonema amabilis
Hydora nitida
Hydrobiosidae
Potamopyrgus antipodarum
Psilachorema bidens
Pycnocentrodes evecta
Zelandoperlinae
Archichauliodes diversus
Tanytarsini
Helicopsyche albescens
Hudsonema aliena
Scirtidae
Cricotopus II
Hydrobiosis parumbripennis
Hydrobiosis type Black Pronotum
Hydrobiosis type checkers
Nesameletus ornatus
Olinga feredayi
Pycnocentria
Pycnocentrodes
Zelandoperla
Zephlebia spectabilis
Austroclima jollyae
Diamesid Blond
Diamesid Brown Orange
Neocurupira hudsonii
Stenoperla cyrene
Terrestial invertebrates
Amelotopsis perscitus
Atalophlebioides cromwelli
Baraeoptera roria
Pirara
Polypedellum
Cricotopus I
Hydrobiosis
Oxyethira albiceps
Orthocladiinae
Eukiefferiella
Tanytarsini I
Hydraena orchymontia
Hydrobiosella
Paroxyethira eatoni/hintoni
Zelolessica cheira
Tanypodini
Olinga feredayii
Aoteapsyche raruraru
Austroperla cyrene
Hydrobiosella stenocerca
Hydrobiosis charadrea
Megaleptoperla grandis
Orchymontia
Paracalliope
Philorheithrus agilis
Polypedilum Type II
Pycnocentria evecta
Terrestrial invertebrate remains
Aoteapsyche colonica
Hydrobiosis frater
Naonella forsythii
Tanytarsus type blunt
Orthoclad Blue Black
Oligochaeta II
Podaena
Zelandoperla fenestrata

Based on studies in:
Austria, Vorderer Finstertaler Lake (Lake or pond)
England, River Cam (River)
Scotland (Estuarine)
New Zealand: Otago, Berwick, Meggatburn (River)
New Zealand: Otago, Blackrock, Lee catchment (River)
New Zealand: Otago, Broad, Lee catchment (River)
New Zealand: South Island, Canton Creek, Taieri River, Lee catchment (River)
New Zealand: Otago, Dempster's Stream, Taieri River, 3 O'Clock catchment (River)
New Zealand: Otago, German, Kye Burn catchment (River)
New Zealand: Otago, Kye Burn (River)
New Zealand: Otago, North Col, Silver catchment (River)
New Zealand: Otago, Sutton Stream, Taieri River, Sutton catchment (River)
New Zealand: Otago, Venlaw, Mimihau catchment (River)
New Zealand: Otago, Little Kye, Kye Burn catchment (River)

This list may not be complete but is based on published studies.
  • Hall SJ, Raffaelli D (1991) Food-web patterns: lessons from a species-rich web. J Anim Ecol 60:823–842
  • Huxham M, Beany S, Raffaelli D (1996) Do parasites reduce the chances of triangulation in a real food web? Oikos 76:284–300
  • Myers, P., R. Espinosa, C. S. Parr, T. Jones, G. S. Hammond, and T. A. Dewey. 2006. The Animal Diversity Web (online). Accessed February 16, 2011 at http://animaldiversity.org. http://www.animaldiversity.org
  • P. H. T. Hartley, Food and feeding relationships in a community of fresh-water fishes, J. Anim. Ecol. 17(1):1-14, from p. 12 (1948).
  • R. Pechlaner, G. Bretschko, P. Gollmann, H. Pfeifer, M. Tilzer and H. P. Weissenbach, Ein Hochgebirgssee (Vorderer Finstertaler See, K htai, Tirol) als Modell des Energietransportes durch ein limnisches Oekosystem, Verh. Dtsch. Zool. Ges. 65:47-56, from p
  • Thompson, RM and Townsend CR. 2005. Energy availability, spatial heterogeneity and ecosystem size predict food-web structure in streams. OIKOS 108: 137-148.
  • Thompson, RM and Townsend, CR. 1999. The effect of seasonal variation on the community structure and food-web attributes of two streams: implications for food-web science. Oikos 87: 75-88.
  • Townsend, CR, Thompson, RM, McIntosh, AR, Kilroy, C, Edwards, ED, Scarsbrook, MR. 1998. Disturbance, resource supply and food-web architecture in streams. Ecology Letters 1:200-209.
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Diseases and Parasites

Hysterothylacium Infection 8. Parasitic infestations (protozoa, worms, etc.)
  • Moravec, F. 1998 Nematodes of freshwater fishes of the neotropical region. 464 p. Praha, Academy of Sciences of the Czech Republic. (Ref. 51153)
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Hysterothylacium Infection (Hysterothylacium sp.). Parasitic infestations (protozoa, worms, etc.)
  • Bunkley-Williams, L. and E.H. Williams Jr. 2002 Nematodes of freshwater fishes of the Neotropical region. (Book review). Caribb. J. Sci. 38(3-4):289-294. (Ref. 46699)
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Enteric Redmouth Disease. Bacterial diseases
  • Horne, M.T. and A.C. Barnes 1999 Enteric redmouth disease (Yersinia ruckeri). p.455-477. In P.T.K. Woo and D.W. Bruno (eds.) Fish Diseases and Disorders, Vol. 3: Viral, Bacterial and Fungal Infections. CAB Int'l. (Ref. 48849)
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Camallanus Infection 16. Parasitic infestations (protozoa, worms, etc.)
  • Moravec, F. 1998 Nematodes of freshwater fishes of the neotropical region. 464 p. Praha, Academy of Sciences of the Czech Republic. (Ref. 51153)
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Aeromonosis. Bacterial diseases
  • Aoki, T. 1999 Motile Aeromonads (Aeromonas hydrophila). p.427-453. In P.T.K. Woo and D.W. Bruno (eds.) Fish Diseases and Disorders, Vol. 3: Viral, Bacterial and Fungal Infections. CAB Int'l. (Ref. 48848)
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General Ecology

Preys on other species of trout and competes with them for food and space (Sublette et al. 1990).

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Life History and Behavior

Behavior

Communication Channels: visual ; tactile ; chemical

Perception Channels: visual ; tactile ; chemical

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Cyclicity

Comments: Feeding most intense at twilight (Sublette et al. 1990).

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Life Cycle

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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Life Expectancy

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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Lifespan, longevity, and ageing

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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Reproduction

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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Spawns in fall or early winter. Eggs hatch in 1-2 months, depending on temperature. Sexually mature in 2nd or 3rd year (or up to 5th year). Typically spawns in more than one year.

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Molecular Biology and Genetics

Molecular Biology

Barcode data: Salmo trutta

The following is a representative barcode sequence, the centroid of all available sequences for this species.


There are 27 barcode sequences available from BOLD and GenBank.

Below is a sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.

See the BOLD taxonomy browser for more complete information about this specimen and other sequences.

ACACGATGATTTTTCTCAACCAACCACAAAGACATTGGCACCCTCTATTTAGTATTTGGTGCCTGAGCCGGGATAGTCGGCACCGCCCTA---AGTCTCTTGATTCGGGCAGAACTCAGCCAACCCGGCGCCCTCCTAGGGGAT---GACCAGATTTATAACGTAATTGTTACAGCCCATGCCTTCGTAATAATTTTCTTTATAGTCATACCAATTATGATCGGCGGCTTTGGAAACTGATTAATCCCTCTCATA---ATCGGAGCCCCCGACATAGCATTCCCCCGAATGAATAACATAAGCTTCTGACTCCTCCCTCCGTCCTTTCTTCTCCTCCTAGCCTCGTCTGGAGTTGAAGCCGGCGCTGGCACAGGATGAACAGTCTACCCCCCTCTAGCCGGCAATCTTGCCCACGCAGGAGCTTCCGTTGACTTA---ACTATTTTCTCCCTCCATTTAGCTGGTATTTCCTCAATTTTGGGGGCCATTAATTTTATTACGACCATTATTAACATAAAACCCCCAGCCATCTCCCAATATCAAACTCCACTTTTTGTTTGGGCCGTGTTAGTCACCGCCGTCCTCTTATTACTCTCCCTCCCTGTTTTAGCAGCA---GGCATTACTATGCTACTCACAGACCGAAATCTTAATACCACTTTCTTTGACCCGGCAGGCGGAGGGGATCCAATCTTATACCAACACCTCTTTTGGTTCTTTGGCCACCCAGAAGTCTATATTCTTATTCTCCCAGGCTTTGGTATAATTTCGCACATCGTTGCGTACTACTCTGGCAAAAAA---GAACCCTTCGGGTATATGGGCATAGTCTGAGCTATGATGGCCATCGGACTCTTAGGCTTTATCGTTTGAGCCCACCATATGTTTACTGTCGGGATAGACGTAGACACTCGTGCCTACTTTACATCTGCCACCATAATTATCGCTATTCCAACTGGGGTAAAAGTATTTAGTTGACTA---GCCACA
-- end --

Download FASTA File

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Statistics of barcoding coverage: Salmo trutta

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 73
Specimens with Barcodes: 95
Species With Barcodes: 1
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Conservation

Conservation Status

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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IUCN Red List Assessment


Red List Category
LC
Least Concern

Red List Criteria

Version
3.1

Year Assessed
2013

Assessor/s
Freyhof, J.

Reviewer/s
Kottelat, M. & Smith, K.

Contributor/s
Kottelat, M.

Justification
A widespread species and overall Least Concern. However, anadromous part of populations (sea trout) and many lacustrine stocks have in many cases markedly declined because of pollution (and possibly from impacts from salmon farming). The phylogeographic structure is almost destroyed by stocking.

European Union 27 = LC. Same rationale as above.


History
  • 2008
    Least Concern
    (IUCN 2008)
  • 2008
    Least Concern
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National NatureServe Conservation Status

Canada

Rounded National Status Rank: NNA - Not Applicable

United States

Rounded National Status Rank: NNA - Not Applicable

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NatureServe Conservation Status

Rounded Global Status Rank: G5 - Secure

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Population

Population
Abundant.

Population Trend
Unknown
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Threats

Major Threats
Locally threatened by water pollution and impacts from salmon farming (sea lice etc.)
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Least Concern (LC)
  • IUCN 2006 2006 IUCN red list of threatened species. www.iucnredlist.org. Downloaded July 2006.
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Management

Conservation Actions

Conservation Actions
No information available.
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Relevance to Humans and Ecosystems

Benefits

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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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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Economic Uses

Comments: Has been used in carcinogen testing (Metcalfe 1989).

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Importance

fisheries: commercial; aquaculture: commercial; gamefish: yes
  • FAO 1996 Aquaculture production statistics 1985-1994. FAO Fish. Circ. 815. 189 p. (Ref. 12228)
  • Flower, S.S. 1935 Further notes on the duration of life in animals. I. Fishes: as determined by otolith and scale-readings and direct observations on living individuals. Proc. Zool. Soc. London 2:265-304. (Ref. 274)
  • Food and Agriculture Organization of the United Nations 1992 FAO yearbook 1990. Fishery statistics. Catches and landings. FAO Fish. Ser. (38). FAO Stat. Ser. 70:(105):647 p. (Ref. 4931)
  • International Game Fish Association 1991 World record game fishes. International Game Fish Association, Florida, USA. (Ref. 4699)
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Risks

Species Impact: Incompatible with native species such as cutthroat trout and Gila trout; protection of native species requires segregation of them from brown trout (Sublette et al. 1990).

Introduced populations in New Zealand exert strong top-down control of communty structure and ecosystem functioning via effects on individual behavior and population distribution and abundance (Townsend 2003).

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Wikipedia

Brown trout

The brown trout (Salmo trutta) is an originally European species of salmonid fish. It includes both purely freshwater populations, referred to Salmo trutta morpha fario and S. trutta morpha lacustris, 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.[3] Sea trout in the UK and Ireland have many regional names, including sewin (Wales), finnock (Scotland), peal (West Country), mort (North West England), and white trout (Ireland).

The lacustrine morph of brown trout is most usually potamodromous, migrating from lakes into rivers or streams to spawn, although evidence indicates 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 nonanadromous morphs coexisting in the same river appear genetically identical.[4] What determines whether or not they migrate remains unknown.

Taxonomy[edit]

The scientific name of the brown trout is Salmo trutta. The specific epithet trutta derives from the Latin trutta, meaning, literally, "trout". Behkne (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.[5]

Range[edit]

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.[6]

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.[7] 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.[8] 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.[9]

The first introductions in Canada occurred in 1886 in Newfoundland and continued through 1933. The only Canadian regions without brown trout are the Yukon and Northwest Territories. Introductions into South America began in 1904 in Argentina. Brown trout are now established in Chile, Peru, and the Falklands.[8] 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.[10] 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.[6] 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) believes all life forms of brown trout—anadromous, riverine and lacustine—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).[6]

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.[6] 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.[8]

Conservation status[edit]

The fish is not considered to be endangered, although, in some cases, 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 which 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.[citation needed]

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.[11] S. trutta morpha fario prefers cold (though in comparison with other "trout", this species has a somewhat higher temperature preference of about 60-65 °F, or 15.5-18.3 °C), and well-oxygenated upland waters, especially large streams in mountainous areas.

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[edit]

A 2.7-kg, 60-cm sea trout, from Galway Bay in the west of Ireland bearing scars from a fishing net
Waxworms are used as live bait for trout fishing.
Corn worms are also excellent bait when trout fishing.
A young brown trout from the River Derwent in North East England
Brown trout from a western Wyoming creek
Brown trout in a creek
Brown trout in Värmland, Sweden, after the first summer

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 (16–32 in) with a maximum length of 140 cm (55 in) and about 60 lb (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 Sept. 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 Mr. 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 fresh water, 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. The Loch Leven strain is more often found in the western United States, while the "German brown" is found more often in the Midwest and East.

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[edit]

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 fishes.[12] Moreover, in brown trout, as in many other fish species, a change in the diet composition normally occurs during the life of the fish,[13] and piscivorous behaviour is most frequent in large brown trout.[14] 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.[15][16]

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.[17][18] 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.[19]

Stocking, farming and non-native brown trout[edit]

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.[20] 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.

Scottish and Irish sea trout populations in recent years have seriously declined, possibly due to infestation by sea lice from salmon farms.[21]

Angling[edit]

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.[22] 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)[23]

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)[24]

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.[25] 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.[26] 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.[27]

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.[28] 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

— Mary Towbridge Townsend, 1897, Outing Magazine, .[29]

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.[30] Outside the US and outside its native range in Europe, introduced brown trout have created "world-class" fisheries in New Zealand,[31] Patagonia[32] and the Falklands.[33]

References[edit]

  1. ^ Freyhof, J. (2012). "Salmo trutta". IUCN Red List of Threatened Species. Version 2012.1. International Union for Conservation of Nature. Retrieved 14 August 2012. 
  2. ^ "Synonyms of Salmo trutta Linnaeus, 1758". Fishbase.org. Retrieved 2014-02-22. 
  3. ^ Trout Science: "Science of Trout"
  4. ^ Aquatic Living Resources: "Lack of genetic differentiation between anadromous and resident sympatric brown trout (Salmo trutta) in a Normandy population."
  5. ^ 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. 
  6. ^ 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. 
  7. ^ "Global Invasive Species Database-Salmo trutta-Distribution". Invasive Species Specialist Group (ISSG) of the IUCN Species Survival Commission. Retrieved 2014-02-01. 
  8. ^ 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. 
  9. ^ 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. 
  10. ^ 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. 
  11. ^ "Climate Change and Freshwater". 11 Feb 2009 <http://www.climate-and-freshwater.info/rivers-temperate-ecoregions/climate-change-species/>.
  12. ^ 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.
  13. ^ 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.
  14. ^ 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.
  15. ^ Elliott, J.M. (1967). The food of trout (Salmo trutta) in a Dartmoor stream. Journal of Applied Ecology, 4(1): 59-71.
  16. ^ 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.
  17. ^ Zimmerman, C.E. & Mosegaard, H. (1992). Initial feeding in migratory brown trout (Salmo trutta L.) alevins. Journal of Fish Biology, 40(4): 647-650.
  18. ^ 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.
  19. ^ 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.
  20. ^ Brown Trout, Salmo trutta Sea Grant. Retrieved 14 February 2010.
  21. ^ Clover, Charles. 2004. The End of the Line: How overfishing is changing the world and what we eat. Ebury Press, London. ISBN 0-09-189780-7
  22. ^ Herd, Andrew Dr (2001). "Beginnings". The Fly. Ellesmere, Shropshire: Medlar Press. pp. 19–74. ISBN 1-899600-19-1. 
  23. ^ Andrew Herd. "Translation-Treatyse of Fysshynge with an Angle Fishes". Flyfishinghistory.com. Retrieved 2014-02-02. 
  24. ^ Walton, Izaak (1653). The Compleat Angler. London. 
  25. ^ McDonald, John (1972). "Gordan and American Fly-fishing". Quill Gordon. New York: Alfred A. Knopf. pp. 34–44. ISBN 0394469895. 
  26. ^ Gingrich, Arnold (1974). The Fishing In Print-A Guided Tour Through Five Centuries of Angling Literature. New York: Winchester Press. pp. 224–225. 
  27. ^ 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. 
  28. ^ Franke, Mary Ann (Fall 1996). "A Grand Experiment—100 Years of Fisheries Management in Yellowstone: Part I". Yellowstone Science 4 (4). 
  29. ^ Townsend, Mary Trowbridge (May 2, 1897). "A Woman's Trout Fishing in Yellowstone Park". Outing Magazine XXX (2): 163. 
  30. ^ Price, Steve. Arkansas Monster Browns. Field and Stream. Retrieved 2014-02-22. 
  31. ^ McGinley, Morgan (January 26, 2010). "A Long Road to World-Class Fly Fishing in New Zealand". New York Times. Retrieved 2014-02-22. 
  32. ^ Kaminsky, Peter (February 11, 2006). "At the End of the World, the Fish Stories Are True". New York Times. Retrieved 2014-02-22. 
  33. ^ 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 

Further reading[edit]

  • "Salmo trutta". Integrated Taxonomic Information System. Retrieved 30 January 2006. 
  • Froese, Rainer and Pauly, Daniel, eds. (2005). "Salmo trutta" in FishBase. 10 2005 version.
  • Clover, Charles. 2004. The End of the Line: How overfishing is changing the world and what we eat. Ebury Press, London. ISBN 0-09-189780-7
  • Heacox, Cecil E. (1974). The Complete Brown Trout. New York: Winchester Press. ISBN 0-87691-129-7. 
  • Graeme Harris, Nigel Milner, ed. (2007). Sea Trout: Biology, Conservation and Management. Wiley. ISBN 9781405129916. 
  • J.L. Bagliniere, G. Maisse, J. Watson (1999). Biology and Ecology of the Brown Sea Trout. Springer Praxis Books. ISBN 1852331178. 
  • Elliot, J.M. (1994). Quantitative Ecology and the Brown Trout. Oxford, UK: Oxford University Press. ISBN 0198540906. 
  • Newton, Chris (2013). The Trout's Tale - The Fish That Conquered an Empire. Ellesmere, Shropshire: Medlar Press. ISBN 978-1-907110-44-3. 
  • Marston, R.B. (Summer 1985). "Brown Trout (Salmo fario)". The American Fly Fisher (Manchester, VT: American Museum of Fly Fishing) 12 (3): 7–8. Retrieved 2014-11-19. 
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Dollaghan

Dollaghan are a variety of brown trout native to Lough Neagh, Northern Ireland, and many of its tributaries. They are a potamodromous migratory trout spending much of the year in the lough, returning to the rivers in autumn to spawn. Dollaghan are much sought after by anglers in County Antrim due to their greater size in comparison to the non-migratory trout found in streams such as the Kells Water, Six Mile Water and River Maine. They are often caught at in the dark in methods very similar to that of fishing for sea trout. Many anglers regard them as an elusive species and call them 'sea trout of lough neagh'. Their weight varies greatly - from small fish of aroiund 1/2 lb to large specimens of over 10 lb.

References


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Names and Taxonomy

Taxonomy

Comments: May hybridize with SALVELINUS FONTINALIS.

See Bernatchez (2001) for a phylogeographic analysis based on mtDNA data.

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