21-517: The East Siberian grayling (Thymallus pallasii) is a grayling in the salmon family Salmonidae . Males can reach a size of 44 cm (17 in). East Siberian grayling was first described to be found at the Kolyma River basin by Peter Simon Pallas . Its distribution range is still insufficiently understood, and is believed to include most of the rivers flowing to the Arctic coast eastward from
42-565: A database covering forms of aquatic life other than finfish. This resulted, in 2006, in the birth of SeaLifeBase . The long-term goal of SeaLifeBase is to develop an information system modelled on FishBase, but including all forms of aquatic life, both marine and freshwater, apart from the finfish which FishBase specialises in. Altogether, there are about 300,000 known species in this category. As awareness of FishBase has grown among fish specialists, it has attracted over 2,480 contributors and collaborators. Since 2000 FishBase has been supervised by
63-500: A species of least concern, and recent genetic work indicates T. pallasii may be part of a larger group, T. arcticus sl. , composed of T. mertensii , pallasii and signifer . Thymallus See text Thymallus , commonly known as graylings , is a genus of freshwater ray-finned fish and the only genus within the subfamily Thymallinae of the family Salmonidae . Although all Thymallus species can be generically called graylings, without specific qualification
84-415: 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
105-558: Is access to tools such as trophic pyramids , identification keys , biogeographical modelling and fishery statistics and there are direct species level links to information in other databases such as LarvalBase , GenBank , the IUCN Red List and the Catalog of Fishes . As of February 2024 , FishBase included descriptions of 35,600 species and subspecies, with 329,500 common names , 64,000 pictures, and references to 61,700 works in
126-541: The Catalog of Fishes 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 . The fishes of this genus are native to
147-997: The Khatanga River , across the East Siberian Plain , and further east to easternmost Siberia, including the rivers in the Chukotka Peninsula as well as rivers of the Sea of Okhotsk basin, such as the Ola River in the Magadan Oblast and the Kukhtuy in Khabarovsk Krai . Thymallus can be distinguished by their elongated, often cylindrical body, greatly enlarged dorsal fin, small mouth and striking dorsal coloration. Adult dorsum color ranges from dark purple to blue/black, and claret red spots are sometimes observed above ventral fins and on
168-422: 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
189-575: The scientific literature . The site has about 700,000 visits per month. The origins of FishBase go back to the 1970s, when the fisheries scientist Daniel Pauly found himself struggling to test a hypothesis on how the growing ability of fish was affected by the size of their gills. Hypotheses, such as this one, could be tested only if large amounts of empirical data were available. At the time, fisheries management used analytical models which required estimates for fish growth and mortality . It can be difficult for fishery scientists and managers to get
210-579: 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 . 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
231-682: The beginnings of a software database along these lines was encoded in 1988. This database, initially confined to tropical fish, became the prototype for FishBase. FishBase was subsequently extended to cover all finfish , and was launched on the Web in August 1996. It is now the largest and most accessed online database for fish in the world. In 1995 the first CD-ROM was released as "FishBase 100". Subsequent CDs have been released annually. The software runs on Microsoft Access which operates only on Microsoft Windows . FishBase covers adult finfish, but does not detail
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#1732863257566252-538: The belly. The body is further decorated with a smattering of small dark spots; these are much more numerous in juveniles. 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. These fishes require cool, well-oxygenated water, preferably with
273-410: The caudal peduncle. Adults can have dark lateral spotting, and the lower caudal lobe is often longer than the upper lobe East-Siberian grayling were first described by Valenciennes (1828) and were described as having a less acute pectoral fin, radiating streaks on the operculum, longer dorsal fin rays, and narrower maxillae than other Thymallus sp. . Additionally, Thymallus sp. can be distinguished by
294-475: The data available in the published literature into some central and easily accessed repository. Such a database would be particularly useful if the data has also been standardised and validated. This would mean that when scientists or managers need to test a new hypothesis, the available data will already be there in a validated and accessible form, and there will be no need to create a new dataset and then have to validate it. Pauly recruited Rainer Froese , and
315-402: The early and juvenile stages of fish. In 1999 a complementary database, called LarvalBase , went online under the supervision of Bernd Ueberschär. It covers ichthyoplankton and the juvenile stage of fishes, with detailed data on fish eggs and larvae , fish identification , as well as data relevant to the rearing of young fish in aquaculture . Given FishBase's success, there was a demand for
336-815: The extension of the upper jaw beyond the anterior of the eye but not to the midpoint of the eye. Thymallus sp. including T. pallasii often have plastic phenotypes distinguished by differences in relative length, rows of spots on dorsal fins and caudal peduncle color. Thymallus spawn polygamously in the spring in rivers and lakes, with males guarding independent territories. Eggs are laid in shallow areas of clear, fast-moving streams with rocky or sandy bottoms, and incubate for between 13 and 18 days before hatching. Adults do not perform any parental care. Juveniles reach sexual maturity at around 2 – 6 years old, and maximum sizes recorded are 515 mm and 488 mm, for females and males, respectively. Grayling live up to 22 years, and are known to have complex local migrations corresponding with
357-654: The grayling ( T. thymallus ) and the Arctic grayling ( T. arcticus ). FishBase FishBase is a global species database of fish species (specifically finfish ). It is the largest and most extensively accessed online database on adult finfish on the web. Over time it has "evolved into a dynamic and versatile ecological tool" that is widely cited in scholarly publications. FishBase provides comprehensive species data, including information on taxonomy , geographical distribution, biometrics and morphology , behaviour and habitats, ecology and population dynamics as well as reproductive, metabolic and genetic data. There
378-428: The information they need on the species that concern them, because the relevant facts can be scattered across and buried in numerous journal articles, reports, newsletters and other sources. It can be particularly difficult for people in developing countries who need such information. Pauly believed that the only practical way fisheries managers could access the volume of data they needed was to assemble and consolidate all
399-753: 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. Thymallus species are distinguished from other members of
420-659: The seasons. Adults are visual predators and stay in depths of 110 – 152 cm. Grayling feed primarily on aquatic and terrestrial insects, aquatic insect larvae, fish, small mammals, and crustacean zooplankton, and often require clear streams to feed. East-Siberian grayling predators include humans, as well as pike ( Esox sp. ). While Thymallus do not have significant commercial economic importance, they are culturally relevant and are harvested massively by anglers. Additionally, grayling require rocky or sandy bottom streams and well oxygenated water- giving them important potential as an indicator species. Thymallus pallasii are considered
441-658: The term "grayling" typically refers to the type species Thymallus thymallus , the European grayling . 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". According to FishBase , 14 species are placed in this genus. However, views differ on their taxonomic rank. Modern reviews and
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