Grayling (Thymallus thymallus)

Scientific name: Thymallus thymallus Linnaeus, 1758

The Grayling (Thymallus thymallus) is a freshwater fish of the family Salmonidae. In the aquarium it needs water at 6–18°C (43–64°F).

Grayling care at a glance

Temperature: 6–18°C (43–64°F)

Biology

Inhabits submontane reaches of rivers with a hard sand or stone bottom and well oxygenated, cold and fast-flowing water. Prefers running, well-oxygenated waters of rivers. In Scandinavia, it occurs in clear lakes and freshened part of northern Baltic basin. Usually lives in hollows behind boulders and shaded water under overhanging vegetation. Gregarious, forms schools. Feeds mainly on insects, nymphs, small worms and crustaceans. Breeds in shallow stretches, usually 20-40 cm deep, or riffles, with moderate current of about 0.5 m/s and clean gravel bottom. Can be captured with natural bait (insect larvae) or with artificial fly. Very sensitive to pollution.

Source: FishBase, licensed CC BY-NC 4.0.

Species facts

Scientific name: Thymallus thymallus
Family: Salmonidae (Salmonids)
Order: Salmoniformes (Salmons)
Class: Actinopterygii (Ray-finned fishes)
Maximum length: 60.0
Common length: 30.0
Depth range: 15 m (49 ft)
Environment: Freshwater; brackish;; pH range: 7.0 - 7.5; dH range: 20 - ? benthopelagic; non-migratory; depth range 15 - ? m
Climate: Temperate
Distribution: Europe: Barent Sea basin west of Urals, Caspian, Black, Baltic, White and North Sea basins, Atlantic westward to Loire drainage; Rh?ne drainage; northern Adriatic basin east to Soca drainage. Introduced over most of southern and central Finland. Appendix III of the Bern Convention (protected fauna).
Conservation status (IUCN): Least Concern (LC)
Threat to humans: Harmless
Uses: Fisheries: commercial; aquaculture: commercial; gamefish: yes; aquarium: public aquariums
Resilience: Medium, minimum population doubling time 1.4 - 4.4 years (K=0.12-0.26; tm=2-6; tmax=14)