The brown trout (''Salmo trutta'') is a
Europe
Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...
an species of
salmonid
Salmonidae is a family of ray-finned fish that constitutes the only currently extant family in the order Salmoniformes . It includes salmon (both Atlantic and Pacific species), trout (both ocean-going and landlocked), chars, freshwater whitefis ...
fish that has been widely introduced into suitable environments globally. It includes purely freshwater populations, referred to as the riverine
ecotype
In evolutionary ecology, an ecotype,Greek: ''οίκος'' = home and ''τύπος'' = type, coined by Göte Turesson in 1922 sometimes called ecospecies, describes a genetically distinct geographic variety, population, or race within a species, ...
, ''Salmo trutta''
morph
Morph may refer to:
Biology
* Morph (zoology), a visual or behavioral difference between organisms of distinct populations in a species
* Muller's morphs, a classification scheme for genetic mutations
* "-morph", a suffix commonly used in tax ...
a
''fario'', a lacustrine ecotype, ''S. trutta'' morpha ''lacustris'', also called the lake trout, and
anadromous
Fish migration is mass relocation by fish from one area or body of water to another. Many types of fish migrate on a regular basis, on time scales ranging from daily to annually or longer, and over distances ranging from a few metres to thousan ...
forms known as the
sea trout
Sea trout is the common name usually applied to anadromous (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 ...
, ''S. trutta'' morpha ''trutta''. The latter migrates to the
ocean
The ocean (also the sea or the world ocean) is the body of salt water that covers approximately 70.8% of the surface of Earth and contains 97% of Earth's water. An ocean can also refer to any of the large bodies of water into which the wo ...
s for much of its life and returns to fresh water only to
spawn
Spawn or spawning may refer to:
* Spawn (biology), the eggs and sperm of aquatic animals
Arts, entertainment, and media
* Spawn (character), a fictional character in the comic series of the same name and in the associated franchise
** '' Spawn: ...
. Sea trout in
Ireland
Ireland ( ; ga, Éire ; Ulster Scots dialect, Ulster-Scots: ) is an island in the Atlantic Ocean, North Atlantic Ocean, in Northwestern Europe, north-western Europe. It is separated from Great Britain to its east by the North Channel (Grea ...
and Britain have many regional names: sewin in
Wales
Wales ( cy, Cymru ) is a Countries of the United Kingdom, country that is part of the United Kingdom. It is bordered by England to the Wales–England border, east, the Irish Sea to the north and west, the Celtic Sea to the south west and the ...
, finnock in
Scotland
Scotland (, ) is a country that is part of the United Kingdom. Covering the northern third of the island of Great Britain, mainland Scotland has a border with England to the southeast and is otherwise surrounded by the Atlantic Ocean to the ...
, peal in the
West Country
The West Country (occasionally Westcountry) is a loosely defined area of South West England, usually taken to include all, some, or parts of the counties of Cornwall, Devon, Dorset, Somerset, Bristol, and, less commonly, Wiltshire, Gloucesters ...
, mort in
North West England
North West England is one of nine official regions of England and consists of the ceremonial counties of England, administrative counties of Cheshire, Cumbria, Greater Manchester, Lancashire and Merseyside. The North West had a population of ...
, and white trout in Ireland.
The
lacustrine
A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much larger ...
morph of brown trout is most usually
potamodromous
Fish migration is animal migration, mass relocation by fish from one area or body of water to another. Many types of fish migrate on a regular basis, on time scales ranging from daily to annually or longer, and over distances ranging from a few ...
, 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.
Taxonomy
The scientific name of the brown trout is ''Salmo trutta''. The
specific
Specific may refer to:
* Specificity (disambiguation)
* Specific, a cure or therapy for a specific illness
Law
* Specific deterrence, focussed on an individual
* Specific finding, intermediate verdict used by a jury in determining the fina ...
epithet ''trutta'' derives from the
Latin
Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...
''trutta'', meaning, literally, "
trout
Trout are species of freshwater fish belonging to the genera '' Oncorhynchus'', ''Salmo'' and ''Salvelinus'', all of the subfamily Salmoninae of the family Salmonidae. The word ''trout'' is also used as part of the name of some non-salmoni ...
".
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
Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...
. ''Systema Naturae'' established the system of
binomial nomenclature
In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...
for
animals
Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, can reproduce sexually, and go through an ontogenetic stage in ...
. ''Salmo trutta'' was used to describe
anadromous
Fish migration is mass relocation by fish from one area or body of water to another. Many types of fish migrate on a regular basis, on time scales ranging from daily to annually or longer, and over distances ranging from a few metres to thousan ...
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.
Range
The native range of brown trout extends from northern
Norway
Norway, officially the Kingdom of Norway, is a Nordic country in Northern Europe, the mainland territory of which comprises the western and northernmost portion of the Scandinavian Peninsula. The remote Arctic island of Jan Mayen and t ...
and
White Sea
The White Sea (russian: Белое море, ''Béloye móre''; Karelian and fi, Vienanmeri, lit. Dvina Sea; yrk, Сэрако ямʼ, ''Serako yam'') is a southern inlet of the Barents Sea located on the northwest coast of Russia. It is su ...
tributaries in Russia in the
Arctic Ocean
The Arctic Ocean is the smallest and shallowest of the world's five major oceans. It spans an area of approximately and is known as the coldest of all the oceans. The International Hydrographic Organization (IHO) recognizes it as an ocean, a ...
to the
Atlas Mountains
The Atlas Mountains are a mountain range in the Maghreb in North Africa. It separates the Sahara Desert from the Mediterranean Sea and the Atlantic Ocean; the name "Atlantic" is derived from the mountain range. It stretches around through Moroc ...
in North Africa. The western limit of their native range is
Iceland
Iceland ( is, Ísland; ) is a Nordic island country in the North Atlantic Ocean and in the Arctic Ocean. Iceland is the most sparsely populated country in Europe. Iceland's capital and largest city is Reykjavík, which (along with its s ...
in the north Atlantic, while the eastern limit is in
Aral Sea
The Aral Sea ( ; kk, Арал теңізі, Aral teñızı; uz, Орол денгизи, Orol dengizi; kaa, Арал теңизи, Aral teńizi; russian: Аральское море, Aral'skoye more) was an endorheic basin, endorheic lake lyi ...
tributaries in
Afghanistan
Afghanistan, officially the Islamic Emirate of Afghanistan,; prs, امارت اسلامی افغانستان is a landlocked country located at the crossroads of Central Asia and South Asia. Referred to as the Heart of Asia, it is bordere ...
and
Pakistan
Pakistan ( ur, ), officially the Islamic Republic of Pakistan ( ur, , label=none), is a country in South Asia. It is the world's List of countries and dependencies by population, fifth-most populous country, with a population of almost 24 ...
.
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. 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
Falmouth ( ; kw, Aberfala) is a town, civil parish and port on the River Fal on the south coast of Cornwall, England, United Kingdom. It has a total resident population of 21,797 (2011 census).
Etymology
The name Falmouth is of English or ...
, to
Melbourne
Melbourne ( ; Boonwurrung/Woiwurrung: ''Narrm'' or ''Naarm'') is the capital and most populous city of the Australian state of Victoria, and the second-most populous city in both Australia and Oceania. Its name generally refers to a met ...
on the sailing ship ''Norfolk''. By 1866, 171 young brown trout were surviving in a
Plenty River
The Plenty River is a perennial river of the Port Phillip catchment, located in the north-eastern Greater Melbourne region of the Australian state of Victoria.
Course and features
The Plenty River rises in the forested slopes of Mount Disappoin ...
hatchery in
Tasmania
)
, nickname =
, image_map = Tasmania in Australia.svg
, map_caption = Location of Tasmania in AustraliaCoordinates:
, subdivision_type = Country
, subdi ...
. 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.
Successful introductions into the
Natal
NATAL or Natal may refer to:
Places
* Natal, Rio Grande do Norte, a city in Brazil
* Natal, South Africa (disambiguation), a region in South Africa
** Natalia Republic, a former country (1839–1843)
** Colony of Natal, a former British colony ...
and
Cape Province
The Province of the Cape of Good Hope ( af, Provinsie Kaap die Goeie Hoop), commonly referred to as the Cape Province ( af, Kaapprovinsie) and colloquially as The Cape ( af, Die Kaap), was a province in the Union of South Africa and subsequen ...
s of
South Africa
South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countri ...
took place in 1890 and 1892, respectively. By 1909, brown trout were established in the mountains of
Kenya
)
, national_anthem = "Ee Mungu Nguvu Yetu"()
, image_map =
, map_caption =
, image_map2 =
, capital = Nairobi
, coordinates =
, largest_city = Nairobi
, ...
. The first introductions into the
Himalayas
The Himalayas, or Himalaya (; ; ), is a mountain range in Asia, separating the plains of the Indian subcontinent from the Tibetan Plateau. The range has some of the planet's highest peaks, including the very highest, Mount Everest. Over 100 ...
in northern India took place in 1868, and by 1900, brown trout were established in
Kashmir
Kashmir () is the northernmost geographical region of the Indian subcontinent. Until the mid-19th century, the term "Kashmir" denoted only the Kashmir Valley between the Great Himalayas and the Pir Panjal Range. Today, the term encompas ...
and
Madras
Chennai (, ), formerly known as Madras ( the official name until 1996), is the capital city of Tamil Nadu, the southernmost Indian state. The largest city of the state in area and population, Chennai is located on the Coromandel Coast of th ...
. In the 1950s and 1960s, , a
French
French (french: français(e), link=no) may refer to:
* Something of, from, or related to France
** French language, which originated in France, and its various dialects and accents
** French people, a nation and ethnic group identified with Franc ...
geologist, began the introduction of several species of salmonids on the remote
Kerguelen Islands
The Kerguelen Islands ( or ; in French commonly ' but officially ', ), also known as the Desolation Islands (' in French), are a group of islands in the sub-Antarctic constituting one of the two exposed parts of the Kerguelen Plateau, a large ...
in the southern
Indian Ocean
The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by th ...
. Of the seven species introduced, only
brook trout
The brook trout (''Salvelinus fontinalis'') is a species of freshwater fish in the char genus ''Salvelinus'' of the salmon family Salmonidae. It is native to Eastern North America in the United States and Canada, but has been introduced elsewhere ...
, ''Salvelinus fontinalis'', and brown trout survived to establish wild populations.
Introduction to Americas
The first introductions in Canada occurred in 1883 in
Newfoundland
Newfoundland and Labrador (; french: Terre-Neuve-et-Labrador; frequently abbreviated as NL) is the easternmost province of Canada, in the country's Atlantic region. The province comprises the island of Newfoundland and the continental region ...
and continued until 1933. The only Canadian regions without brown trout are
Yukon
Yukon (; ; formerly called Yukon Territory and also referred to as the Yukon) is the smallest and westernmost of Canada's three territories. It also is the second-least populated province or territory in Canada, with a population of 43,964 as ...
and the
Northwest Territories
The Northwest Territories (abbreviated ''NT'' or ''NWT''; french: Territoires du Nord-Ouest, formerly ''North-Western Territory'' and ''North-West Territories'' and namely shortened as ''Northwest Territory'') is a federal territory of Canada. ...
. Introductions into South America began in 1904 in
Argentina
Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...
. Brown trout are now established in
Chile
Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...
,
Peru
, image_flag = Flag of Peru.svg
, image_coat = Escudo nacional del Perú.svg
, other_symbol = Great Seal of the State
, other_symbol_type = Seal (emblem), National seal
, national_motto = "Fi ...
, and the
Falklands
The Falkland Islands (; es, Islas Malvinas, link=no ) is an archipelago in the South Atlantic Ocean on the Patagonian Shelf. The principal islands are about east of South America's southern Patagonian coast and about from Cape Dubouzet ...
.
[ Sea-run forms of brown trout exceeding are caught by local anglers on a regular basis.
]
The first introductions into the U.S. started in 1883 when Fred Mather
Fred Mather (January 2, 1833, in Albany, New York – February 14, 1900) was a United States pisciculturist and a writer and editor on fishing topics.
Life and career
In 1854 he became interested in the lead mines of Potosi, Wisconsin, and afte ...
, a New York pisciculturist and angler
Angler may refer to:
* A fisherman who uses the fishing technique of angling
* ''Angler'' (video game)
* The angler, ''Lophius piscatorius'', a monkfish
* More generally, any anglerfish in the order Lophiiformes
* '' Angler: The Cheney Vice Presi ...
, under the authority of the U.S. Fish Commissioner, Spencer Baird
Spencer Fullerton Baird (; February 3, 1823 – August 19, 1887) was an American naturalist, ornithologist, ichthyologist, herpetologist, and museum curator. Baird was the first curator to be named at the Smithsonian Institution. He eventually ...
, obtained brown trout eggs from a Baron Lucius von Behr, president of the . The von Behr brown trout came from both mountain streams and large lakes in the Black Forest
The Black Forest (german: Schwarzwald ) is a large forested mountain range in the state of Baden-Württemberg in southwest Germany, bounded by the Rhine Valley to the west and south and close to the borders with France and Switzerland. It is t ...
region of Baden-Württemberg
Baden-Württemberg (; ), commonly shortened to BW or BaWü, is a German state () in Southwest Germany, east of the Rhine, which forms the southern part of Germany's western border with France. With more than 11.07 million inhabitants across a ...
.[ The original shipment of "von Behr" brown trout eggs were handled by three hatcheries, one on ]Long Island
Long Island is a densely populated island in the southeastern region of the U.S. state of New York (state), New York, part of the New York metropolitan area. With over 8 million people, Long Island is the most populous island in the United Sta ...
, the Cold Spring Hatchery operated by Mather, one in Caledonia, New York
Caledonia is a town in Livingston County, New York, United States. The population was 4,255 at the 2010 census. The town contains the village of Caledonia. The town is in the northwestern part of the county and is southwest of Rochester. It is ...
, operated by pisciculturalist Seth Green
Seth Benjamin Green ( ''né'' Gesshel-Green; born February 8, 1974) is an American actor, producer, and writer. Green's film debut came with a role in the comedy-drama film ''The Hotel New Hampshire'' (1984), and he went on to have supporting ...
, and other hatchery in Northville, Michigan
Northville is a city in Oakland and Wayne counties in the U.S. state of Michigan. The population was 6,119 at the 2020 census.
Northville is a suburb of Metro Detroit and is located about west of the city of Detroit and northeast of Ann Arbo ...
. 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'').[
In April 1884, the U.S. Fish Commission released 4900 brown trout fry into the Baldwin River, a tributary of the ]Pere Marquette River
The Pere Marquette River is a river in Michigan in the United States. The main stream of this river is long,U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map accessed November 21, 2011 running fro ...
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.[ 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.][
]
Conservation status
The fish is not considered to be endangered
An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inva ...
, although some individual stocks
Stocks are feet restraining devices that were used as a form of corporal punishment and public humiliation. The use of stocks is seen as early as Ancient Greece, where they are described as being in use in Solon's law code. The law describing ...
are under various degrees of stress mainly through habitat degradation, overfishing
Overfishing is the removal of a species of fish (i.e. fishing) from a body of water at a rate greater than that the species can replenish its population naturally (i.e. the overexploitation of the fishery's existing fish stock), resulting in th ...
, and artificial propagation leading to introgression
Introgression, also known as introgressive hybridization, in genetics is the transfer of genetic material from one species into the gene pool of another by the repeated backcrossing of an interspecific hybrid with one of its parent species. Intr ...
. Increased frequency of excessively warm water temperatures in high summer causes a reduction in dissolved oxygen
Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as wel ...
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
Eutrophication is the process by which an entire body of water, or parts of it, becomes progressively enriched with minerals and nutrients, particularly nitrogen and phosphorus. It has also been defined as "nutrient-induced increase in phytopla ...
of rivers due to pollution
Pollution is the introduction of contaminants into the natural environment that cause adverse change. Pollution can take the form of any substance (solid, liquid, or gas) or energy (such as radioactivity, heat, sound, or light). Pollutants, the ...
—often from the use of agricultural fertilizer
A fertilizer (American English) or fertiliser (British English; see spelling differences) is any material of natural or synthetic origin that is applied to soil or to plant tissues to supply plant nutrients. Fertilizers may be distinct from ...
s within the drainage basin
A drainage basin is an area of land where all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, t ...
.
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 organism
In biology, an organism () is any living system that functions as an individual entity. All organisms are composed of cells (cell theory). Organisms are classified by taxonomy into groups such as multicellular animals, plants, and ...
s. For example, in Canada
Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...
's Bow River
The Bow River is a river in Alberta, Canada. It begins within the Canadian Rocky Mountains and winds through the Alberta foothills onto the prairies, where it meets the Oldman River, the two then forming the South Saskatchewan River. These w ...
, a non-native alga
Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular mi ...
''Didymosphenia geminata''—common name rock snot
''Didymosphenia geminata'', commonly known as didymo or rock snot, is a species of diatom that produces nuisance growths in freshwater rivers and streams with consistently cold water temperatures and low nutrient levels. It is native to the nort ...
(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
An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the syste ...
in which the trout reside.
In small streams, brown trout are important predators of macroinvertebrates
Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate s ...
, and declining brown trout populations in these specific areas affect the entire aquatic food web
A food web is the natural interconnection of food chains and a graphical representation of what-eats-what in an ecological community. Another name for food web is consumer-resource system. Ecologists can broadly lump all life forms into one ...
.
Global climate change is also of concern. ''S. trutta'' morpha ''fario'' prefers well-oxygenated water in the temperature range of . ''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
The Younger Dryas (c. 12,900 to 11,700 years BP) was a return to glacial conditions which temporarily reversed the gradual climatic warming after the Last Glacial Maximum (LGM, c. 27,000 to 20,000 years BP). The Younger Dryas was the last stage ...
period, and fell during the warmer Bølling-Allerød event.
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.
The brown trout is a medium-sized fish, growing to or more and a length of about in some localities, although in many smaller rivers, a mature weight of or less is common. ''S. t. lacustris'' reaches an average length of with a maximum length of and about .
The spawning behaviour of brown trout is similar to that of the closely related Atlantic salmon
The Atlantic salmon (''Salmo salar'') is a species of ray-finned fish in the family Salmonidae. It is the third largest of the Salmonidae, behind Siberian taimen and Pacific Chinook salmon, growing up to a meter in length. Atlantic salmon are ...
. 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
The Manistee River ( '), seldom referred to as the Big Manistee River, runs U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map, accessed November 21, 2011 through the northwestern Lower Peninsula of ...
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
Forage fish, also called prey fish or bait fish, are small pelagic fish which are preyed on by larger predators for food. Predators include other larger fish, seabirds and marine mammals. Typical ocean forage fish feed near the base of the food ...
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
Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...
from the streambed
A stream bed or streambed is the bottom of a stream or river (bathymetry) or the physical confine of the normal water flow (channel). The lateral confines or channel margins are known as the stream banks or river banks, during all but flood st ...
, other fish, frogs, mice, birds, and insects flying near the water's surface. The high dietary reliance upon insect larvae
A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle.
The ...
, pupae
A pupa ( la, pupa, "doll"; plural: ''pupae'') is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in their ...
, nymphs
A nymph ( grc, νύμφη, nýmphē, el, script=Latn, nímfi, label=Modern Greek; , ) in ancient Greek folklore is a minor female nature deity. Different from Greek goddesses, nymphs are generally regarded as personifications of nature, are typ ...
, and adults allows trout to be a favoured target for fly fishing
Fly fishing is an angling method that uses a light-weight lure—called an artificial fly—to catch fish. The fly is cast using a fly rod, reel, and specialized weighted line. The light weight requires casting techniques significantly diffe ...
. 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
300px, Feeder Goldfish are common baitfish.
Bait fish (or baitfish) are small-sized fish caught and used by anglers as bait to attract larger predatory fish, particularly game fish. Baitfish species are typically those that are common and bree ...
.
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
Scotland (, ) is a country that is part of the United Kingdom. Covering the northern third of the island of Great Britain, mainland Scotland has a border with England to the southeast and is otherwise surrounded by the Atlantic Ocean to the ...
and Germany
Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...
.
Brown trout rarely form hybrids with other species; if they do, they are almost invariably infertile. One such example is the tiger trout
The tiger trout (''Salmo trutta'' × ''Salvelinus fontinalis'') is a sterile, intergeneric hybrid of the brown trout (''Salmo trutta'') and the brook trout (''Salvelinus fontinalis''). Pronounced vermiculations in the fish's patterning gave rise ...
, a hybrid with the brook trout
The brook trout (''Salvelinus fontinalis'') is a species of freshwater fish in the char genus ''Salvelinus'' of the salmon family Salmonidae. It is native to Eastern North America in the United States and Canada, but has been introduced elsewhere ...
.
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. Moreover, in brown trout, as in many other fish species, a change in the diet composition normally occurs during the life of the fish, and piscivorous behaviour is most frequent in large brown trout. 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.
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. 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.
Stocking, farming and non-native brown trout
The species has been widely introduced for sport fishing
Recreational fishing, also called sport fishing or game fishing, is fishing for leisure, exercise or competition. It can be contrasted with commercial fishing, which is professional fishing for profit; or subsistence fishing, which is fishing ...
into North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...
, South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...
, Australia
Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...
, New Zealand
New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...
, and many other countries, including Bhutan
Bhutan (; dz, འབྲུག་ཡུལ་, Druk Yul ), officially the Kingdom of Bhutan,), is a landlocked country in South Asia. It is situated in the Eastern Himalayas, between China in the north and India in the south. A mountainous ...
, 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, Michigan
Baldwin is a village in the U.S. state of Michigan. The population was 863 at the 2020 census. It is the county seat of Lake County. The village is located on the boundary between Webber Township on the north and Pleasant Plains Township o ...
.[Brown Trout, ''Salmo trutta''](_blank)
Sea Grant. Retrieved 14 February 2010. 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
Allopatric speciation () – also referred to as geographic speciation, vicariant speciation, or its earlier name the dumbbell model – is a mode of speciation that occurs when biological populations become geographically isolated from ...
genome
In the fields of molecular biology and genetics, a genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding ge ...
s) probably exist only in isolated places, for example in Corsica
Corsica ( , Upper , Southern ; it, Corsica; ; french: Corse ; lij, Còrsega; sc, Còssiga) is an island in the Mediterranean Sea and one of the 18 regions of France. It is the fourth-largest island in the Mediterranean and lies southeast of ...
or in high alpine valleys on the European mainland.
Farming of brown trout has included the production of infertile triploid
Polyploidy is a condition in which the cells of an organism have more than one pair of ( homologous) chromosomes. Most species whose cells have nuclei ( eukaryotes) are diploid, meaning they have two sets of chromosomes, where each set contain ...
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
Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Sets of chromosomes refer to the number of maternal and paternal chromosome copies, respectively ...
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
The brown trout has been a popular game fish
Game fish, sport fish or quarry refer to popular fish pursued by recreational anglers, and can be freshwater or saltwater fish. Game fish can be eaten after being caught, or released after capture. Some game fish are also targeted commerciall ...
of European anglers for centuries. It was first mentioned in angling literature as "fish with speckled skins" by Roman author Aelian Aelian or Aelianus may refer to:
* Aelianus Tacticus, Greek military writer of the 2nd century, who lived in Rome
* Casperius Aelianus, Praetorian Prefect, executed by Trajan
* Claudius Aelianus, Roman writer, teacher and historian of the 3rd centu ...
(''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. 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
Recreational fishing, also called sport fishing or game fishing, is fishing for leisure, exercise or competition. It can be contrasted with commercial fishing, which is professional fishing for profit; or subsistence fishing, which is fishing ...
, especially fly fishing. One of the most prominent fish described in the work is the brown trout of English rivers and streams:
The renowned ''The Compleat Angler'' (1653) by Izaak Walton
Izaak Walton (baptised 21 September 1593 – 15 December 1683) was an English writer. Best known as the author of ''The Compleat Angler'', he also wrote a number of short biographies including one of his friend John Donne. They have been colle ...
is replete with advice on "the trout":
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
Frederic Maurice Halford (13 April 1844 – 5 March 1914), pseudonym Detached Badger, was a wealthy and influential British angler and fly fishing author. Halford is most noted for his development and promotion of the dry fly technique on Englis ...
, a British angler, author published ''Dry-Fly Fishing in Theory and Practice
''Dry-Fly Fishing in Theory and Practice'' (1889) is British author and angler Frederic M. Halford's second and most influential book on dry fly fishing. It followed ''Floating Flies and How to Dress Them'' (1886) and this pair of books initiated ...
'', 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
Theodore Gordon (September 18, 1854 – May 1, 1915) was an American writer who fished the Catskill region of New York State in the late 19th century through the early 20th century. Though he never published a book, Gordon is often called the ...
, 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 River
The Neversink River (also called Neversink Creek in its upper course) is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map accessed April 1, 2011 tributary of the Delaware River in southeastern Ne ...
s. In the early 20th century, British angler and author G. E. M. Skues
George Edward MacKenzie Skues, usually known as G. E. M. Skues (1858–1949), was a British lawyer, author and fly fisherman most noted for the invention of modern-day nymph fishing and the controversy it caused with the Chalk stream dry fly d ...
pioneered nymphing techniques for brown trout on English chalk streams. His ''Minor Tactics of the Chalk Stream
''Minor Tactics of the Chalk Stream and Kindred Studies'' is a fly fishing book written by G. E. M. Skues published in London in 1910. ''Minor Tactics'' was Skues's first book and set the stage for his ascendancy as the inventor of nymph fishi ...
'' (1910) began a revolution in fly fishing techniques for trout. 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.
Introductions of brown trout into the American West
The Western United States (also called the American West, the Far West, and the West) is the region comprising the westernmost states of the United States. As American settlement in the U.S. expanded westward, the meaning of the term ''the Wes ...
created new angling opportunities, none so successful from an angling perspective as was the introduction of browns into the upper Firehole River
The Firehole River is located in northwestern Wyoming, and is one of the two major tributaries of the Madison River. It flows north approximately from its source in Madison Lake on the Continental Divide to join the Gibbon River at Madison Junc ...
in Yellowstone National Park
Yellowstone National Park is an American national park located in the western United States, largely in the northwest corner of Wyoming and extending into Montana and Idaho. It was established by the 42nd U.S. Congress with the Yellowston ...
in 1890. 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:
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. Outside the U.S. and outside its native range in Europe, introduced brown trout have created "world-class" fisheries in New Zealand, Patagonia
Patagonia () refers to a geographical region that encompasses the southern end of South America, governed by Argentina and Chile. The region comprises the southern section of the Andes Mountains with lakes, fjords, temperate rainforests, and gl ...
, and the Falklands
The Falkland Islands (; es, Islas Malvinas, link=no ) is an archipelago in the South Atlantic Ocean on the Patagonian Shelf. The principal islands are about east of South America's southern Patagonian coast and about from Cape Dubouzet ...
.
References
Further reading
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*
*Clover, Charles. 2004. ''The End of the Line: How overfishing is changing the world and what we eat''. Ebury Press, London.
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External links
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Life Cycle of the Sea Trout
''Salmo trutta'' Linnaeus 1758
GLANSIS Species FactSheet (Distributional information for North America)
{{Authority control
Salmo
Freshwater fish of Europe
Fish of the United States
Fish of the Western United States
Fish of Pakistan
Fish described in 1758
Taxa named by Carl Linnaeus
Freshwater fish of North America