Bristol zoo has successfully bred Potosi pupfish, a species of fish extinct in the wild. Staff at the zoo said they were "thrilled" when spawning behaviour was observed soon after the fish were introduced from London Zoo.
Bristol Zoo and ZSL London Zoo are the only two institutions in the UK working together to safeguard the species, which are classed as extinct in the wild, through a conservation breeding programme. A handful of private breeders in Spain, Mexico and America are also keeping them.
It is hoped numbers will be boosted in captivity through co-ordinated breeding. The Potosi pupfish belongs to the killifish family, which is made up of over 1,200 different species of small, egg-laying ray-finned fish. They are silver with a lovely blue finish which makes them mesmerising to watch.
Potosi pupfish were native to North America and Mexico where they lived in freshwater. They are now classed as "extinct in the wild" according to the International Union for Conservation of Nature Red List of threatened species. Extinction of the Potosi pupfish may have been caused by the demise of their natural habitats – clear springs, ponds and ditches with dense vegetation and green algae.