Species threatened with extinction Last known female Roi du Doubs has new offspring
The last known female of the fish species "Roi du Doubs" in Switzerland has reproduced again. Due to the old age of the animal, it could have been the last offspring.
05.05.2026, 10:54
05.05.2026, 11:15
SDA
The rescue of the endangered species now depends on the young fish, as the Swiss Fishing Association (SFV) and the nature conservation organizations Pro Natura and WWF announced on Tuesday.
The female fish, named "Océane", is the last known specimen of this species to be found in Switzerland. It was discovered in the Doubs River in the Jura in 2023 and has been kept in the aquarium at the Citadel of Besançon in France since 2025. Every spring for the past three years, this female has been brought together with males from a different river in the Rhône catchment area. In spring 2026, the animal reproduced for the third time in a row.
The juveniles from the first two offspring are kept at the Aquatis aquarium in Lausanne and at Basel Zoo. The larvae that hatched this spring are being reared in Besançon F. According to the association, this offspring represents the last chance to preserve the genetic uniqueness of the Roi du Doubs.
National action plan unsuccessful so far
The time window to prevent the extinction of this species is now tiny, the associations emphasized. If the federal government, cantons and municipalities do not act very quickly, Switzerland will witness the disappearance of the "Roi du Doubs".
The fish, also known as the Rhône Streber (Zingel asper), is strictly protected in Switzerland and is only found in the Doubs. There is a national action plan for its protection, which is managed by the Federal Office for the Environment (FOEN) in collaboration with the cantons of Jura and Neuchâtel.
However, the measures proposed in this plan since 2015 have so far been unsuccessful, according to the associations. Important measures have not yet been implemented. For example, the free migration of fish must be enabled, sediment transport restored and water quality improved.
