The London Zoo is urgently seeking a female mate for the last-known males of a critically endangered fish species.
Zoo officials say the Mangarahara cichlid is thought to be extinct in the wild and that two of the last known individuals -- both male -- are in the zoo's aquarium. A third is in the Berlin zoo.
Officials say the species' habitat in Madagascar has dried up due to dam construction.
"It might be too late for their wild counterparts, but if we can find a female, it's not too late for the species. Here at ZSL London Zoo we have two healthy males, as well as the facilities and expertise to make a real difference," London Zoo aquarium curator Brian Zimmerman said in a statement.
"We are urgently appealing to anyone who owns or knows someone who may own these critically endangered fish, which are silver in colour with an orange-tipped tail, so that we can start a breeding programme here at the Zoo to bring them back from the brink of extinction."
The zoo on Friday asked aquarium owners and fish collectors to come forward it they know of any living females "so that a vital conservation breeding program can be started."
According to the BBC, a previous attempt to breed the cichlid with a female in Berlin ended in disaster when the male fish killed her. Zimmerman told the news agency the behavior is common with cichlids.
A team at the zoo hope that aquarium owners, fish collectors and hobbyists will know if any females are in existence. Officials say a worldwide search of zoo and aquarium organizations has so far proved fruitless.