The Mangarahara cichlid is a fish native to the rivers of Madagascar — or, at least, it was. It's thought that the fish has gone extinct in the wild, and the only three survivors are in a pair of European zoos. But these three fish are all male, old, ugly... and liable to kill any fish that tries to breed with them.
At least, that's what happened to the last known female member of the species, as a breeding program with the male at the Berlin Zoo ended with it killing its would-be partner, which has to rank as one of the most spectacularly grim ways to doom one's own species to extinction. As London Zoo aquarium curator Brian Zimmerman explains to the BBC, that is a distressingly common result for species like this, and it now means they have to appeal to private owners worldwide in a last-ditch effort to find one more female:
"It's a fairly common thing with cichlids. They are unusual fish compared to many in that they practice pair bonding and parental care of the eggs and the fry, so there's a lot of tussling that goes on between them... They are not a particularly beautiful fish - they are gorgeously ugly, they are unusual. They are more a connoisseur's type of fish. They need quite a bit of space; the males are bigger than your hand, and they need a decent tank."
Both of the specimens at the London Zoo are about 12 years old, which places them towards the end of their normal lifespan. The Zoological Society of London has already reached out to zoos and aquariums in search of a female, which means the only chance now is for a private collector to come forward. But Zimmerman says the odds of finding a female in time aren't good, and even then it may well just be delaying the inevitable; even if new cichlids were indeed produced, Zimmerman says the growing global shortage of available freshwater means this species might no longer have an environment to return to.
Still, if you, by some miracle, do actually know of a female Mangarahara cichlid — and judging by the above description, they're rather unmistakable — then the people to contact are at firstname.lastname@example.org.