Grayling [fish]
CRCritically Endangered

Grayling [fish]

Thymallus thymallus

Thymallus thymallus, harjus, 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.

Photo: Wikimedia Commons (CC) via https://en.wikipedia.org/wiki/Thymallus_thymallus

01Classification

Taxonomy & Classification

Kingdom

Animalia

Phylum

Chordata

Order

Salmoniformes

Family

Salmonidae

Genus

Thymallus

Grayling [fish] belongs to the family Salmonidae, order Salmoniformes, within the unknown class.

02Description

Species Profile

Thymallus thymallus, harjus, 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.

European Grayling populations have declined dramatically due to habitat degradation, water pollution, and river modifications that have fragmented their spawning grounds. Climate change is exacerbating these pressures by altering water temperatures and flow regimes that this cold-water species requires. Overfishing and competition from introduced species have further contributed to population declines across much of their historical range.

Key Facts

IUCN StatusCritically Endangered (CR)
GroupOther invertebrates
03Habitat

Habitat & Distribution

FRESHWATERMajorFRESHWATERMajor
04Threats

Threats

!

IUCN Red List: Critically Endangered

European Grayling populations have declined dramatically due to habitat degradation, water pollution, and river modifications that have fragmented their spawning grounds. Climate change is exacerbating these pressures by altering water temperatures and flow regimes that this cold-water species requires. Overfishing and competition from introduced species have further contributed to population declines across much of their historical range.

Climate change and rising water temperatures

HighOngoing

Habitat degradation and river channelization

HighOngoing

Water pollution from agricultural and industrial sources

HighOngoing

Competition from introduced fish species

MediumOngoing

Overfishing and angling pressure

MediumOngoing
07National Status

National vs Global Threat Status

How this species is assessed at the national level compared to its IUCN global status (CR).

CountryNational StatusGlobal StatusComparison
EULCLeast ConcernCRCritically EndangeredLower local risk
EULCLeast ConcernCRCritically EndangeredLower local risk

National Red List data sourced from the National Red List Project (nationalredlist.org, ZSL) and country-specific Red List authorities.

Community

Community Sightings

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07Sources

Sources & Attribution

How to Cite

IUCN: IUCN (2025). The IUCN Red List of Threatened Species. Version 2025-1. Available at: https://www.iucnredlist.org. doi:10.2305/IUCN.UK.2025-1.RLTS

GBIF: GBIF.org (2025). GBIF Home Page. Available at: https://www.gbif.org

National Red Lists: ZSL (2025). National Red List. Zoological Society of London. Available at: https://www.nationalredlist.org

This page: SpeciesRadar (2025). Grayling [fish] (Thymallus thymallus). SpeciesRadar: Intelligence for Earth's Biodiversity. Available at: https://speciesradar.org/species/grayling-fish

Full citation guide & data usage terms