Thymallus

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Thymallus
Temporal range: Pleistocene to Present [1]
Arctic Grayling Thymallus arcticus arcticus.jpg
Arctic grayling ( Thymallus arcticus )
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Salmoniformes
Family: Salmonidae
Subfamily: Thymallinae
Genus: Thymallus
Linck, 1790
Type species
Thymallus thymallus
Species
(see text)

Thymallus is a genus of freshwater fish in the salmon family Salmonidae; it is the only genus of subfamily Thymallinae. The type species is Thymallus thymallus, the grayling. The species in the genus are generically called graylings, but without qualification this also refers specifically to T. thymallus.

Contents

Distribution

The fishes of this genus are native to the northern parts of the Palearctic and Nearctic realms, ranging from the United Kingdom and northern Europe across Eurasia to Siberia, as well as northern North America. T. thymallus, the grayling, is widespread in Europe, and T. arcticus, the Arctic grayling, is widespread throughout Eurasia east of the Ural Mountains and in the Nearctic. The other species have more localized ranges in northern Asia.

Appearance

Thymallus species are distinguished from other members of the salmon family by their larger scales, their small mouths with teeth on the maxillary bone, and most striking of all, their showy, sail-like dorsal fins. This fin is longer in males and highly colourful, with spots of red, orange, purple or green. The body is also colourful; the dorsal surface is a dark purplish to bluish black or gray, grading to dark blue or silver gray on the flanks and gray or white on the belly. The body is further decorated with a smattering of small dark spots; these are much more numerous in juveniles.

Four Arctic grayling (T. arcticus) from the Colville River of Alaska Grayling caught in the Colville River. North Slope, Alaska.jpg
Four Arctic grayling (T. arcticus) from the Colville River of Alaska

The longest of the graylings is the Arctic grayling, T. arcticus, at a maximum length of 76 cm (30 in) and a maximum weight of 3.8 kg (8.4 lb). T. thymallus, while somewhat shorter - 60 cm (24 in) - may weigh significantly more, 6.7 kg (15 lb). The fishes of this genus may live for 18 years or more.

Ecology and reproduction

These fishes require cool, well-oxygenated water, preferably with a swift current; they are found in large, sandy- or gravel-bottomed rivers and lakes, but T. thymallus may occasionally be found in brackish conditions. Generally omnivorous, they feed primarily on crustaceans, insects, and zooplankton.

The grayling species, typically for salmonids, spawn in rivers and do not guard their brood, although they do conceal their eggs in silt. The spawning behavior of the Arctic grayling may be typical for the genus Thymallus.

As they are highly sensitive to changes in water quality, Thymallus fishes may be considered indicator species; T. arcticus has largely disappeared from the Great Lakes Basin.

Human use

Catch of grayling (Thymallus thymallus), Lapland Harjus.JPG
Catch of grayling (Thymallus thymallus), Lapland

Due to their agreeable taste and attractive form, the grayling species are valued as food and game fishes, and they are occasionally seen in public aquaria. The most economically important of these fishes, for which fisheries and aquaculture operations exist, are the grayling (T. thymallus) and the Arctic grayling (T. arcticus).

Name

The name of the genus Thymallus first given to grayling (T. thymallus) described in the 1758 edition of Systema Naturae by Swedish zoologist Carl Linnaeus originates from the faint smell of the herb thyme, which emanates from the flesh. Thymallus derives from the Greek θύμαλλος, "thyme smell". [2]

Species

According to FishBase, 14 species are placed in this genus. [3] However, views differ on their taxonomic rank.

The Catalog of Fishes also lists the species Thymallus baikalolenensis Matveyev, Samusenok, Pronin & Telpukhovsky, 2005, but recognises T. yaluensis only as a subspecies. [4] An old controversy exists over the status of Baikal black vs white graylings, T. baicalensis and T. brevipinnis. Modern research supports the view that they are not separate taxa, but alternative ecological forms of T. baicalensis. [5]

Related Research Articles

Thyme Herb with culinary, medicinal and ornamental uses

Thyme is the herb of some members of the genus Thymus of aromatic perennial evergreen herbs in the mint family Lamiaceae. Thymes are relatives of the oregano genus Origanum. They have culinary, medicinal, and ornamental uses, and the species most commonly cultivated and used for culinary purposes is Thymus vulgaris.

<i>Coregonus</i>

Coregonus is a diverse genus of fish in the salmon family (Salmonidae). The Coregonus species are known as whitefishes. The genus contains at least 68 described extant taxa, but the true number of species is a matter of debate. The type species of the genus is Coregonus lavaretus.

Salmonidae Family of ray-finned fishes

Salmonidae is a family of ray-finned fish, the only living family currently placed in the order Salmoniformes. It includes salmon, trout, chars, freshwater whitefishes, and graylings, which collectively are known as the salmonids. The Atlantic salmon and trout of the genus Salmo gives the family and order their names.

Lake Baikal Freshwater rift lake in southern Siberia, Russia

Lake Baikal is a rift lake located in southern Siberia, Russia, between Irkutsk Oblast to the northwest and the Buryat Republic to the southeast.

Grayling (species)

The grayling is a species of freshwater fish in the salmon family Salmonidae. It is the only species of the genus Thymallus native to Europe, where it is widespread from the United Kingdom and France to the Ural Mountains in Russia, but does not occur in the southern parts of the continent. It was introduced to Morocco in 1948, but it does not appear to have become established there.

Grayling or Greyling may refer to:

<i>Hucho taimen</i>

The taimen, also known as Siberian taimen, Siberian giant trout, and Siberian salmon, is a species of fish in the salmon family of order Salmoniformes. These fish are found in rivers in Russia and adjacent regions, and are harvested throughout the year.

<i>Leuciscus</i>

Leuciscus is a genus of fish belonging to the family Cyprinidae. They are inland water fishes commonly called Eurasian daces. The genus is widespread from Europe to Siberia. Species broadly distributed in Europe include the common dace Leuciscus leuciscus and the ide L. idus.

Arctic grayling Species of fish

Arctic grayling is a species of freshwater fish in the salmon family Salmonidae. T. arcticus is widespread throughout the Arctic and Pacific drainages in Canada, Alaska, and Siberia, as well as the upper Missouri River drainage in Montana. In the U.S. state of Arizona, an introduced population is found in the Lee Valley and other lakes in the White Mountains. They were also stocked at Toppings Lake by the Teton Range and in various lakes in the high Uinta Mountains in Utah, as well as various alpine lakes of the Boulder Mountain chain in central Idaho.

<i>Thymallus yaluensis</i>

Thymallus yaluensis is a putative species of freshwater fish, a grayling in the salmon family Salmonidae. It is endemic to the upper Yalu River in Korea, on the Chinese border.

Acipenser is a genus of sturgeons. With 17 living species, it is the largest genus in the order Acipenseriformes. They are native to Europe, Asia and North America, and most species are threatened.

<i>Salvelinus</i>

Salvelinus is a genus of salmonid fish often called char or charr; some species are called "trout". Salvelinus is a member of the subfamily Salmoninae within the family Salmonidae. The genus has a northern circumpolar distribution, and most of its members are typically cold-water fish that primarily inhabit fresh waters. Many species also migrate to the sea.

<i>Comephorus</i>

Comephorus, known as the golomyankas or Baikal oilfish, are a genus comprising two species of peculiar, sculpin fishes endemic to Lake Baikal in Russia. Comephorus is the only genus in the family Comephoridae. Golomyankas are pelagic fishes which make the main food source of the Baikal seal.

Freshwater whitefish

The freshwater whitefish are fishes of the subfamily Coregoninae, which contains whitefishes and ciscoes, and is one of three subfamilies in the salmon family Salmonidae. Apart from the subfamily Coregoninae, the family Salmonidae includes the salmon, trout, and char species of the subfamily Salmoninae, and grayling species of the subfamily Thymallinae. Freshwater whitefish are distributed mainly in relatively cool waters throughout the northern parts of the Northern Hemisphere.

Lenok

Lenoks are a genus, Brachymystax, of salmonid fishes native to rivers and lakes in Mongolia, Kazakhstan, wider Siberia (Russia), Northern China, and Korea.

T. tricolor may refer to:

Montana Arctic grayling

The Montana Arctic grayling is a North American freshwater fish in the salmon family Salmonidae. The Montana Arctic grayling, native to the upper Missouri River basin in Montana and Wyoming, is a disjunct population or subspecies of the more widespread Arctic grayling. It occurs in fluvial and adfluvial, lacustrine forms. The Montana grayling is a species of special concern in Montana and had candidate status for listing under the national Endangered Species Act. It underwent a comprehensive status review by the U.S. Fish and Wildlife Service, which in 2014 decided not to list it as threatened or endangered. Current surviving native populations in the Big Hole River and Red Rock River drainages represent approximately four percent of the subspecies' historical range.

References

  1. Sepkoski, Jack (2002). "A compendium of fossil marine animal genera". Bulletins of American Paleontology. 364: 560. Retrieved 2008-01-07.
  2. Ingram, A.; Ibbotson, A.; Gallagher, M. "The Ecology and Management of the European Grayling Thymallus thymallus (Linnaeus)" (PDF). East Stoke, Wareham, U.K.: Institute of Freshwater Ecology. p. 3. Retrieved 2014-02-27.CS1 maint: uses authors parameter (link)
  3. Froese, Rainer and Pauly, Daniel, eds. (2015). Species of Thymallus in FishBase . May 2015 version.
  4. Eschmeyer F. Catalog of Fishes: yaluensis, Thymallus arcticus (search "yaluensis") California Academy of Sciences (15.6.2015 version)
  5. Knizhin IB, Weiss SJ, Sushnik S (2006) Graylings of Baikal lake basin (Thymallus, Thymallidae): Diversity of forms and their taxonomic status. Journal of Ichthyology 46, 418-435.

Further reading