Gwyniad
Rare whitefish found only in one Welsh lake
The gwyniad is a freshwater fish from the salmon family. It lives only in Llyn Tegid in North Wales. Scientists first described it in 1848. Its status as a unique species is debated by experts.
- Found only in Llyn Tegid in North Wales
- Threatened by invasive ruffe eating its eggs
- First described scientifically in 1848
- Eggs moved to reservoir for conservation
What it is
The gwyniad is a ray-finned fish in the salmon family. It belongs to the genus Coregonus, which holds various whitefish species. This small fish has a silvery body typical of its group. It is distinct for being endemic to a single location in the United Kingdom. The name comes from Greek words describing the angle of the pupil. The specific name honours Thomas Pennant, a naturalist who wrote about the fish in the eighteenth century.
Where it lives
This species lives only in Llyn Tegid, also known as Bala Lake. The lake sits in the upper River Dee drainage system in Gwynedd. The fish occupies the deeper parts of the water column. It stays in the benthopelagic zone, which is near the bottom but not on it. During warmer months, the fish moves up towards the surface to feed. This daily vertical migration helps it find food in changing temperatures.
How it lives
The gwyniad feeds in the open water and near the lake bed. It moves vertically each day to follow food sources. In summer, it rises to warmer surface layers. The introduced ruffe fish poses a threat to its survival. Ruffe eat the eggs and young fry of the gwyniad. This predation pressure affects the population dynamics in the lake. The fish must compete for resources in its limited habitat.
Breeding and life cycle
Specific details on spawning times and egg development are not provided in the available records. The species reproduces within its native lake environment. Conservation efforts have involved moving eggs to other waters. This suggests that breeding success is critical for its survival. The transfer of eggs aims to create a backup population away from threats.
Fish and people
The fish is named after Thomas Pennant, who documented it in 1769. He classified it under a different scientific name at that time. Today, it is recognized as a unique part of Welsh natural heritage. Its primary significance is ecological and scientific. It represents a rare example of a localized freshwater species.
Status and threats
Water quality decline in Llyn Tegid threatens the population. The invasive ruffe, introduced in the 1980s, eats gwyniad eggs. To protect the species, conservationists moved eggs to Llyn Arenig Fawr. This transfer took place between 2003 and 2007. Taxonomic debates continue, with some studies questioning if it is a separate species. Major databases still list it as distinct.
Questions people ask about Gwyniad
Where does the gwyniad live?
It is endemic to Llyn Tegid, also called Bala Lake, in Gwynedd, North Wales. It lives in the deep parts of the lake and moves up in summer.
Why is the gwyniad threatened?
Its main threats are poor water quality and the ruffe, an invasive fish introduced in the 1980s that eats gwyniad eggs and young fry.
Is the gwyniad a distinct species?
Major databases list it as distinct, but some morphological reviews find little evidence to separate it from the common whitefish.
Good reading and sources
The facts on this page come from the Wikipedia article "Gwyniad", written by its contributors and used under the CC BY-SA 4.0 licence, and from its Wikidata record (CC0). EveryFish rewrote the text in its own words, with AI assistance, and compares every page with the article to make sure no passage is copied. It may be reused under the same CC BY-SA 4.0 licence with a link back.
It may contain mistakes, and figures change over time. Nothing here is investment or buying advice. If something is wrong, tell us. Last refreshed 2026-11-15.
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