- Grayling (genus)
name = "Thymallus"
Pleistoceneto Present [cite journal
last = Sepkoski
first = Jack
title = A compendium of fossil marine animal genera
journal = Bulletins of American Paleontology
volume = 364
pages = p.560
date = 2002
url = http://strata.ummp.lsa.umich.edu/jack/showgenera.php?taxon=611&rank=class
accessdate = 2008-01-07 ]
image_width = 250px
Arctic grayling("T. arcticus arcticus")
subfamilia = Thymallinae
genus = "Thymallus"
genus_authority = Linck, 1790
"Thymallus" is a
genusof freshwater fishin the salmonfamily (family Salmonidae) of order Salmoniformes; it is the only genus of subfamilyThymallinae. The type speciesis "T. thymallus," the grayling. The genus's five distinct speciesare generically called graylings, but without qualification this also refers specifically to "T. thymallus."
The fishes of this genus are native to the northern parts of the
Nearcticand Palearctic ecozones, ranging from the United Kingdomand northern Europeacross Eurasiato Siberia, as well as northern North America. "T. thymallus," the grayling proper, is widespread in Europe, and "T. arcticus arcticus," the Arctic grayling, is widespread throughout Eurasia east of the Ural Mountainsand in the Nearctic. The other species and "T. arcticus" subspecieshave more localized ranges.
The "Thymallus" species are distinguished from other members of the
salmonfamily by their larger scales, their small mouths with teethon the maxillarybone, 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. The largest of the graylings in terms of length is the Arctic grayling("T. arcticus arcticus") at a maximum length of 76 cm (30 in) and a maximum weight of 3.8 kg (8.4 lb); other subspecies of "T. arcticus" are typically half this length or less. The grayling proper, "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.
As they are highly sensitive to changes in water quality, "Thymallus" fishes may be considered
indicator species; "T. arcticus arcticus" has largely disappeared from the Great Lakes Basin. These fishes require cool, well-oxygenated water, preferably with a swift current; they are found in large sandy- or gravelly-bottomed rivers and lakes, but "T. thymallus" may occasionally be found in brackishconditions. 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 graylingmay be typical for the "Thymallus" species.
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 aquacultureoperations exist, are the Arctic grayling("T. arcticus arcticus") and the graylingproper ("T. thymallus").
The generic name "Thymallus" derives from the Greek "θύμαλλος," a name for the grayling.
Franz Steindachner(1834-1919) classified the Adriatic trout("Salmo obtusirostris") as "Thymallus microlepis," but that name is not considered valid.
**"T. arcticus arcticus" – Arctic grayling
**"T. arcticus baicalensis" – Baikal black grayling
**"T. arcticus mertensii"
**"T. arcticus pallasi" – East Siberian grayling
*"T. brevirostris" – Mongolian grayling
*"T. grubii" – Amur grayling
*"T. nigrescens" – Kosogol grayling
*"T. thymallus" – Grayling
Wikimedia Foundation. 2010.