Salmo trutta fario

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River trout
Bachforelle Zeichnung.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Salmoniformes
Family: Salmonidae
Genus: Salmo
Species:
Subspecies:
S. t. fario
Trinomial name
Salmo trutta fario

Salmo trutta fario, sometimes called the river trout, [2] is a river-dwelling freshwater predatory fish from the genus Salmo of the family Salmonidae. It is one of the three main subspecies of the brown trout ( Salmo trutta ), besides sea trout ( Salmo trutta trutta ) and the lacustrine trout ( Salmo trutta lacustris ).

Contents

Description

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

Habitat

Like other salmonids, river trout live in cool, fast-flowing, oxygen-rich, clear waters with gravel or sandy riverbeds. Their native ranges occur across almost all of Europe, from Portugal on the Iberian Peninsula to the Volga in Russia, and are found as far north as Lapland. They can be found in most northern Mediterranean and western Black Sea tributaries but not in Greece, Central Anatolia and the Caucasus regions or on Corsica, Sardinia and Sicily islands.

River trout are faithful to their habitat, leaving the home range stream for smaller upstream headwaters to reproduce. Even after being disturbed, they return to their traditional sites. The adult river trout requires its territory. During the day, it is hidden in the shadows of the river bank, facing upstream.

Depending on size and habitat, they feed mainly on insects and larvae, small baitfish (such as European bullhead), small crustaceans, snails and other water animals. Cannibalism has also been frequently observed among river trout. They are fast-swimming pursuit predators, but in faster-flowing rivers and streams, they are usually opportunistic and will take prey that is floating past by the current.

Reproduction

River trout in the "Subaqueous Vltava" exhibition, Prague Salmo trutta Prague Vltava 1.jpg
River trout in the "Subaqueous Vltava" exhibition, Prague

River trout spawn between October and January in the northern hemisphere, and introduced populations in the southern hemisphere spawn between May and June. The fish uses rapid fanning of the tail and caudal fin on a rock riverbed to make several shallow pits, into which about 1,000 to 1,500 reddish eggs 4–5 mm (0.16–0.20 in) in size are laid. The fish larvae emerge after two to four months.

Ecology

The river trout has special significance as a host fish for the glochidia of the freshwater pearl mussel (Margaritifera margaritifera). [3]

Other forms

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

Hybrids

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

Fishing

Well camouflaged river trout in a small stream Bachforelle Stadtbach.JPG
Well camouflaged river trout in a small stream
River trout caught with the help of a fly Bachforelle 1.png
River trout caught with the help of a fly

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

River trout makes an excellent fish dish.

Angling

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

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

Research use

The fish has been used as a bio-indicator species in freshwater systems due to their sensitive nature. They are a well-established ‘model organism’ in aquatic toxicology research, especially for heavy metal bioaccumulation. [4]

Related Research Articles

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Trout is a generic common name for numerous species of carnivorous freshwater ray-finned fishes belonging to the genera Oncorhynchus, Salmo and Salvelinus, all of which are members of the subfamily Salmoninae in the family Salmonidae. The word trout is also used for some similar-shaped but non-salmonid fish, such as the spotted seatrout/speckled trout.

<span class="mw-page-title-main">Smallmouth bass</span> Species of freshwater fish

The smallmouth bass is a species of freshwater fish in the sunfish family (Centrarchidae) of the order Perciformes. It is the type species of its genus Micropterus, and is a popular game fish sought by anglers throughout the temperate zones of North America, and has been spread by stocking—as well as illegal introductions—to many cool-water tributaries and lakes in Canada and more so introduced in the United States. The maximum recorded size is approximately 27 inches (69 cm) and 12 pounds (5.4 kg).

<span class="mw-page-title-main">Trout cod</span> Species of fish

The trout cod or bluenose cod, is a large predatory freshwater fish of the genus Maccullochella and the family Percichthyidae, closely related to the Murray cod. It was originally widespread in the south-east corner of the Murray-Darling river system in Australia, but is now an endangered species.

<span class="mw-page-title-main">Brown trout</span> Species of fish

The brown trout is a species of salmonid ray-finned fish and the most widely distributed species of the genus Salmo, endemic to most of Europe, West Asia and parts of North Africa, and has been widely introduced globally as a game fish, even becoming one of the world's worst invasive species outside of its native range.

<span class="mw-page-title-main">Rainbow trout</span> Fresh-water species of fish

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<i>Salmo</i> Genus of fishes

Salmo is a genus of ray-finned fish from the subfamily Salmoninae of family Salmonidae, and is part of the tribe Salmonini along with the sister genera Salvelinus and Salvethymus. Almost all Salmo species are native only in the Old World, the only exception being the Atlantic salmon, which is also naturally found across the North Atlantic in eastern North America.

<span class="mw-page-title-main">Atlantic salmon</span> Species of fish

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<span class="mw-page-title-main">Brook trout</span> Species of fish

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<span class="mw-page-title-main">Coastal cutthroat trout</span> Subspecies of fish

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<i>Galaxias fontanus</i> Species of fish endemic to Tasmania, Australia

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<i>Salmo dentex</i> Species of fish

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<i>Salmo marmoratus</i> Species of fish

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<span class="mw-page-title-main">Vindel River</span> River in Sweden

The Vindel River is a river in northern Sweden. It is a tributary to Ume River and the biggest tributary river in Sweden. It lends its name to the Vindelfjällens Nature Reserve, one of the largest protected areas in Europe, totaling 562,772 ha. Since it is partially located within the reserve, it is permanently protected from hydroelectric development. Downstream from where Vindelälven merges with Umeälven Sweden's largest hydropower plant is located. Considering that the river is not unregulated all the way to the ocean, but just in the part of it formally called Vindelälven, the decision to call it "unregulated" or "permanently protected from hydropower" is to be taken with a grain of salt. The river Vindel and its tributaries were important routes for transporting timber in northern Sweden, up until 1976. To ease the movement of logs downstream, wooden dams were constructed, side streams were cut off and tributaries were straightened and cleared. These changes significantly affected the river ecosystem and populations of wild fish, mammals, mussels and other species of aquatic and riparian habitats. The changes therefore negatively impact the favourable conservation status of species and habitats within the Vindel River Natura 2000 network site. Actions to restore the tributaries of the Vindel River to a more natural state are considered a priority by the Swedish environmental protection agency, the Västerbotten county administrative board, and the EU under the Habitats Directive and the Water Framework Directive (WFD). The general objective of the Vindel River LIFE project was to achieve a ‘good status’ for the waters of the Vindel River with reference to the Water Framework Directive, and ‘good conservation status’ for the species in the project area under the Habitats Directive. The aim was to reduce the negative impacts of fragmentation and channelisation caused by timber-floating infrastructure in tributaries of the Vindel River system. The work was focused on a number of river stretches, altogether spanning just over 44 km, with the aim of removing 73% of the obstructions to natural river flow, placing large boulders and fallen trees in the water to simulate natural conditions and to reconnect streams to the tributaries to open up breeding areas for migrating fish. The Vindel River LIFE project restored streams in the tributaries of the Vindel River basin, by removing timber-floating infrastructure, replacing large obstacles into the water, and creating and restoring fish spawning grounds. These ecosystem restoration measures resulted in improved water quality, and improvements in conditions for protected species, in line with national and EU policy. The project’s work had clear socio-economic benefits in the project area.

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<i>Salmo farioides</i> Species of fish

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References

  1. Freyhof, J. (2011). "Salmo trutta". IUCN Red List of Threatened Species . 2011: e.T19861A9050312. doi: 10.2305/IUCN.UK.2008.RLTS.T19861A9050312.en . Retrieved 12 November 2021.
  2. John Gunn, editor (2004), Encyclopedia of Caves and Karst Science, New York/London: Taylor & Francis, p. 1278. ISBN   1-57958-399-7.
  3. Mitchell, Daniel (2011). Pecor, Keith; Dewey, Tanya (eds.). "Margaritifera margaritifera". Animal Diversity Web. Retrieved 31 March 2023.
  4. Dvorak, Petr; Roy, Koushik; Andreji, Jaroslav; Liskova, Zuzana Dvorakova; Mraz, Jan (March 2020). "Vulnerability assessment of wild fish population to heavy metals in military training area: Synthesis of a framework with example from Czech Republic". Ecological Indicators. 110: 105920. doi:10.1016/j.ecolind.2019.105920. S2CID   209594927.

Literature