Thymallus

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Thymallus
Temporal range: Pleistocene to Present [1]
Arctic Grayling Thymallus arcticus arcticus.jpg
Arctic grayling ( Thymallus arcticus )
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Salmoniformes
Family: Salmonidae
Subfamily: Thymallinae
Gill, 1885
Genus: Thymallus
Linck, 1790
Type species
Thymallus thymallus
Species

See text

Thymallus or graylings is a genus of freshwater salmonid ray-finned fish (family Salmonidae) and the only genus within the subfamily Thymallinae. Although all Thymallus species can be generically called graylings, without specific qualification the term "grayling" typically refers to the type species Thymallus thymallus , the European grayling.

Contents

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]

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 salmonid 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. [8]

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).

Related Research Articles

<span class="mw-page-title-main">Salmonidae</span> Family of ray-finned fishes

Salmonidae is a family of ray-finned fish that constitutes the only currently extant family in the order Salmoniformes, consisting of 11 extant genera and over 200 species collectively known as "salmonids" or "salmonoids". The family includes salmon, trout, char, graylings, freshwater whitefishes, taimens and lenoks, all coldwater mid-level predatory fish that inhabit the subarctic and cool temperate waters of the Northern Hemisphere. The Atlantic salmon, whose Latin name became that of its genus Salmo, is also the eponym of the family and order names.

<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, and Balkans on the south-east, 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:

<span class="mw-page-title-main">Arctic grayling</span> Species of fish

The 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 lakes in the high Uinta Mountains in Utah, as well as alpine lakes of the Boulder Mountains (Idaho) in central Idaho.

<span class="mw-page-title-main">Amur grayling</span> Species of fish

The Amur grayling is a freshwater species of fish of the family Salmonidae, found in the Amur drainage in Russia and China and also the Onon and Kherlen drainages in Mongolia. It is sometimes difficult to differentiate the species with the Lower Amur grayling. It is an edible fish in Russian far east and Heilongjiang Province of China.

The East Siberian grayling(Thymallus pallasii) is a grayling in the salmon family Salmonidae. Males can reach a size of 44 cm (17 in).

Thymallus yaluensis, also known as Yalu grayling, 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.

<span class="mw-page-title-main">Freshwater whitefish</span> 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.

Batrachocottus is a genus of freshwater ray-finned fishes belonging to the family Cottidae, the typical sculpins. These fishes are endemic to the Lake Baikal watershed in Russia.

<span class="mw-page-title-main">Montana Arctic grayling</span> 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.

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

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

Thymallus brevipinnis is a species of freshwater ray-finned fish belonging to the subfamily Thymallinae, the graylings, part of the family Salmonidae. This species is endemic to Lake Baikal in Siberia where it is benthopelagic. Some workers regard this taxon as a junior synonym of Thymallus baicalensis.

Thymallus ligericus, 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.

<span class="mw-page-title-main">Kamchatka grayling</span> Species of fish

The Kamchatka grayling is a grayling in the salmon family Salmonidae. The fish grows up to 50 cm (20 in). It is found in freshwater habitats of the Russian Far East, including the Kamchatka Peninsula, eastern part of Magadan Oblast and northwards to the southern Chukchi Peninsula.

<span class="mw-page-title-main">Mongolian grayling</span> Species of fish

The Mongolian grayling is a freshwater species of fish of the genus Thymallus endemic to the landlocked rivers in Mongolia, Inner Mongolia Province of China and nearby parts of Russian far east. It is considered to be the largest grayling species in the world, and hence viewed as an auspicious sign by local tribes.

<span class="mw-page-title-main">Upper Yenisei grayling</span> Species of fish

The Upper Yenisei grayling is a freshwater species of fish of the genus Thymallus found in the upstream of Yenisei River and western Mongolia.

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

The Lower Amur grayling is a freshwater species of fish of the genius Thymallus found in the downstream of Amur river on the border of the Russian far east and Heilongjiang Province of China. It is a rather newly discovered fish species, while often being mistaken as Amur grayling.

The yellow-spotted grayling is a brackish species of fish of the genus of Thymallus found in Khabarovsk and Primorsky Krai of the Russian Far East. They were also found in the Sea of Japan and Sea of Okhotsk. They usually live near or on the bottom of the water body.

The Kosogol grayling is a freshwater species of fish of the genus of Thymallus endemic to the Mongolian Lake of Kosogol. They usually live near or on the bottom of the water body.

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.
  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.
  8. Smoliński, Szymon; Glazaczow, Adam (4 December 2019). "Cascading effects of temperature alterations on trophic ecology of European grayling (Thymallus thymallus)". Scientific Reports. 9 (1): 18358. doi: 10.1038/s41598-019-55000-5 . ISSN   2045-2322 . Retrieved 29 November 2023.