Aquarists at Bristol Zoo Gardens have bred an endangered freshwater fish which is now extinct in the wild.
Experts at the Zoo obtained a group of Potosi pupfish from ZSL London Zoo earlier this year and have just reported a batch of six-week old fry which are currently a few centimetres long.
The Potosi pupfish, Cyprinodon alvarezi, is native to Mexico and is listed on the IUCN Red List of Threatened Species as being extinct in the wild.
Bristol Zoo told Practical Fishkeeping: "Bristol Zoo and ZSL London Zoo are the only two institutions in the UK working together to safeguard this species through a conservation programme.
"There are a handful of private breeders in Spain, Mexico and America who are also keeping them."
The 6cm pupfish which comes from El Potosi in Nuevo Leon, Mexico, is a non-seasonal killifish and reportedly difficult to keep in aquaria.
It is thought to have become extinct in the wild through the loss of its habitat - clear springs, ponds and ditches - which have become choked with algae and vegetation.
Jonny Rudd successfully bred the threatened Asian arowana last year. You can find out more about this spawning success in an interview with Rudd in the September issue of Practical Fishkeeping.