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-salmonid fish such as Cynoscion nebulosus, the spotted seatrout or speckled trout.
The brown trout is a European species of salmonid fish that has been widely introduced into suitable environments globally. It includes purely freshwater populations, referred to as the riverine ecotype, Salmo trutta morpha fario, a lacustrine ecotype, S. trutta morpha lacustris., and anadromous forms known as the sea trout, S. trutta morpha trutta. The latter migrates to the oceans for much of its life and returns to fresh water only to spawn. Sea trout in Ireland and Britain have many regional names: sewin in Wales, finnock in Scotland, peal in the West Country, mort in North West England, and white trout in Ireland.
Salmo is a genus of fish in the salmon family Salmonidae that includes the European species of salmon and trout, among them the familiar Atlantic salmon Salmo salar and the brown trout Salmo trutta. The natural distribution of Salmo also extends to Northern Africa and to Western Asia around the Black Sea basin. The single Salmo species naturally found in the Atlantic North America is the Atlantic salmon, whereas the salmon and trout of the Pacific basin belong to another genus, Oncorhynchus. The generic name Salmo derives from the Latin salmō (salmon). The number of distinct species and subspecies in Salmo is a debated issue. Atlantic salmon and brown trout are widespread species, while most of the other taxa are narrowly distributed forms endemic to single watersheds.
The Atlantic salmon is a species of ray-finned fish in the family Salmonidae. It is the 3rd largest of the Salmonidae and can grow up to a meter in length. Mongolian Taimen, and Pacific Chinook Salmon can be larger, with Taimen reportedly able to grow to 6 ft long. It is found in the northern Atlantic Ocean and in rivers that flow into this ocean. Most populations of this fish species are anadromous, hatching in streams and rivers but moving out to sea as they grow where they mature, after which the adult fish seasonally move upstream again to spawn.
The powan is a kind of freshwater whitefish endemic to two lochs in Scotland, Loch Lomond and Loch Eck. It has been successfully introduced in two other sites, Loch Sloy and the Carron Valley Reservoir.
The Arctic char or Arctic charr is a cold-water fish in the family Salmonidae, native to alpine lakes and arctic and subarctic coastal waters. Its distribution is Circumpolar North. It spawns in fresh water and populations can be lacustrine, riverine, or anadromous, where they return from the ocean to their fresh water birth rivers to spawn. No other freshwater fish is found as far north; it is, for instance, the only fish species in Lake Hazen on Ellesmere Island in the Canadian Arctic. It is one of the rarest fish species in Britain and Ireland, found mainly in deep, cold, glacial lakes, and is at risk from acidification. In other parts of its range, such as the Nordic countries, it is much more common, and is fished extensively. In Siberia, it is known as golets and it has been introduced in lakes where it sometimes threatens less hardy endemic species, such as the small-mouth char and the long-finned char in Elgygytgyn Lake.
Sea trout is the common name usually applied to anadromous forms of brown trout, and is often referred to as Salmo trutta morpha trutta. Other names for anadromous brown trout are sewin (Wales), peel or peal, mort, finnock (Scotland), white trout (Ireland) and salmon trout (culinary). The term sea trout is also used to describe other anadromous salmonids—coho salmon, brook trout, Arctic char, cutthroat trout and Dolly Varden. Even some non-salmonid species are also commonly known as sea trout—Northern pikeminnow and members of the weakfish family (Cynoscion).
Salmo trutta fario, sometimes called the river trout, and also known by the name of its parent species, the brown trout, is a predatory fish of the family Salmonidae and a subspecies or morph of the brown trout species, Salmo trutta, which also includes sea trout and a lacustrine trout. Depending on the supply of food, river trout measure 20 to 80 cm (0.7–2.6 ft) in length; exceptionally they may be up to 1 m (3.3 ft) long and weigh up to over 13 kg (29 lb). Their back is olive-dark brown and silvery blue, red spots with light edges occur towards the belly, the belly itself is whitish yellow. River trout usually attains a weight of up to 2 kg (4.4 lb). They can live for up to 18 years.
The Sevan trout is an endemic fish species of Lake Sevan in Armenia, known as ishkhan in Armenian. It is a salmonid fish related to the brown trout.
Lough Melvin is a lake in the northwest of the island of Ireland on the border between County Leitrim and County Fermanagh. It is internationally renowned for its unique range of plants and animals.
Gillaroo is a variety of trout which eats primarily snails and is only proven to inhabit Lough Melvin in Ireland.
Ohrid trout or the Lake Ohrid brown trout is an endemic species of trout in Lake Ohrid and in its tributaries and outlet, the Black Drin river, in North Macedonia and Albania. Locally, the fish is known as охридска пастрмка in Macedonian and koran in Albanian.
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, County Tyrone and County Londonderry due to their greater size in comparison to the non-migratory trout found in streams such as the Ballinderry River Six Mile Water, Moyola River and River Main. They are often caught in the dark using 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 around 1/2 lb to large specimens of around 20 lb. There are four strains of brown trout in Ireland: Dollaghan, Gillaroo, Sonaghan and Ferox. The Dollaghan is thought to have evolved from sea trout which were land locked many years ago.
Salmo aphelios is a species of trout, a salmonid fish endemic to Lake Ohrid in North Macedonia and Albania in the Balkans.
Salmo dentex is a variety of trout, a freshwater fish in the family Salmonidae, found in the western Balkans. Until recently the identity, biological distinctness and species status of the dentex trout were not properly clarified, but genetic data now suggest it is not a monophyletic unit that could be distinguished from other salmonids as a separate species.
Salmo marmoratus is a species of freshwater fish in the family Salmonidae. It is characterized by a distinctive marbled color pattern and high growth capacity. The marble trout is found in only handful drainages and rivers of the Adriatic basin in Italy, Slovenia, Croatia, Bosnia and Herzegovina, and Montenegro, while in Albania, the species is considered most likely extirpated.
Salmo platycephalus, known as the flathead trout, Ala balik or the Turkish trout, is a type of trout, a fish in the family Salmonidae. It is endemic to southeastern Turkey. It is known only from one population, which occupies three streams, tributaries of the Zamantı River in the Seyhan River basin. The population itself is abundant, but subject to threat by habitat loss, since the range is small. Also, predation of juveniles by introduced rainbow trout may cause population decline. The species is classified as critically endangered.
Salmo cettii, or the Mediterranean trout, is a species of trout, a freshwater fish in the family Salmonidae. It lives in the Mediterranean region in Corsica, Sardinia, Sicily, and on the Italian mainland in the Magra drainage and further south. It is a nonmigratory fish which lives in streams and in karstic resurgences. It is smaller than 40 cm (16 in) in length. It is sometimes referred to Salmo trutta macrostigma, which depending on concept is either a more widespread Mediterranean taxon, or a taxon endemic to Algeria.
The Abant trout, is a salmonid fish native to Lake Abant in northern Anatolia. It was initially described as a subspecies of the brown trout Salmo trutta, but later considered a full species. On the basis of crossing experiments and mtDNA sequences, Kalayci et al. (2018) however proposed that it should be considered a local strain within Salmo trutta, with no distinct species status.
Salmo rhodanensis, or the Rhône trout, is a salmonid fish, a putative species of trout resident in the Rhône river drainage in France and Switzerland. It was previously considered as belonging to Salmo trutta. Salmo rhodanensis is an exclusively freshwater fish, and is uniquely characterized by four broad black bars on its body: behind gill opening, under dorsal base, above anal fin origin, and at the base of the tail.
