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.

Modern reviews [4] [5] and the Catalog of Fishes [6] also list additional species including Thymallus nikolskyi Kaschenko, 1899, Thymallus baicalolenensis Matveyev et al., 2005 and Thymallus ligericus Persat et al, 2019. 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. [7]

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> Genus of fishes

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.

<i>Thymallus thymallus</i> Species of fish

Thymallus thymallus, the grayling or European 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>Leuciscus</i> Genus of fishes

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.

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 feshwater and estuarine systems of Eurasia and North America, and most species are threatened. Several species also known to enter near-shore marine environments in the Atlantic, Arctic and Pacific oceans.

<i>Comephorus</i> Genus of fishes

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 Subfamily of fishes

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.

Chinese sleeper Species of fish

The Chinese sleeper, also known as the Amur sleeper, is a species of freshwater sleeper native to Amur River basin in eastern Asia with introduced populations in other regions of Eurasia. It is currently the only known member of its genus.

Lenok Genus of fishes

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:

Batrachocottus is a genus of fish endemic to Lake Baikal in Russia. This genus of sculpins (Cottoidea) is variously considered to belong either to the family Cottocomephoridae, Cottidae or Abyssocottidae.

Montana Arctic grayling Subspecies of fish

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.

Thymallus baicalensis, also known as the Baikal black grayling, is a Siberian freshwater fish species in the salmon family Salmonidae.

The Loire grayling is a European freshwater fish species in the salmon family Salmonidae. The species is endemic to the upper Loire drainage in France, where it lives in medium to large foothill, canyon and plateau rivers of the mountainous regions.

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. Dyldin, Y. V.; L. Hanel; V. I. Romanov; J. Plesník (2017). "A review of the genus Thymallus (Pisces: Salmoniformes: Salmonidae: Thymallinae) with taxonomic notes". Bulletin Lampetra. VIII: 103–126.
  5. Weiss, S. J., D. V. Gonçalves, G. Secci-Petretto, G. K. Englmaier, A. Gomes-Dos-Santos, G. P. J. Denys, H. Persat, A. Antonov, C. Hahn, E. B. Taylor and E. Froufe (2021) Global systematic diversity, range distributions, conservation and taxonomic assessments of graylings (Teleostei: Salmonidae; Thymallus spp.). Organisms Diversity & Evolution: [1-18]. (published online 25 Nov. 2020)
  6. Eschmeyer F. [https://researcharchive.calacademy.org/research/ichthyology/catalog/fishcatmain.asp Catalog of Fishes. California Academy of Sciences (1.3.2021 version)
  7. 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.