The Gwyniad (Coregonus pennantii) is a freshwater whitefish native to Bala Lake (or Llyn Tegid) in northern Wales.
The population is threatened by deteriorating water quality and by the Ruffe, a fish introduced to the lake in the 1980s and now eating the eggs and fry of gwyniad. As a conservation measure, eggs of gwyniad have been transferred to Llyn Arenig Fawr, another nearby lake.
In Britain the gwyniad is usually considered a population belong. By FishBase and by IUCN, it is listed as a distinct species of the Coregonus genus, C. pennantii.
The Gwyniad is currently listed as Critically Endangered by the IUCN.