Wild kin. The rediscovery of Mangarahara cichlids in Madagascar might one day provide a mate for this male (left) at the London Zoo.

(left) LondonZoo; (right) Brian Zimmerman

Wild kin. The rediscovery of Mangarahara cichlids in Madagascar might one day provide a mate for this male (left) at the London Zoo.

New Hope for an Endangered Fish in Madagascar

Staff Writer

Even for an imperiled species, the Mangarahara cichlid was on its last fins. The colorful fish was thought to have vanished from the wild, and only two individuals remain in captivity—both aging males. But thanks to a serendipitous chain of events, a small population was discovered in Madagascar last month, the Zoological Society of London (ZSL) announced.

“This is a very exciting discovery,” says Michele Thieme, a conservation biologist with the World Wildlife Fund in Washington, D.C., who didn’t participate in the discovery. “It’s rare to find a fish species that was feared extinct in the wild.”

The Mangarahara cichlid (Ptychochromis insolitus) is one of several species of cichlids native to Madagascar. They are interesting from an evolutionary perspective because they retain many ancestral traits of cichlid forbears, says Melanie Stiassny, an ichthyologist at the American Museum of Natural History in New York City. When she revised the species’ taxonomy in 2006, she dubbed it “insolitus,” which means unusual, because of its fine-toothed scales and other features.   

To survive in the wild, this cichlid needs clear, deep pools and swift, shallow water. But its habitat—the Mangarahara and Amboaboa river systems—are mostly dry now, their water diverted for rice and other crops. And deforestation has added to silt to streams that feed into the rivers. “This is clearly an endangered species,” Stiassny says. Previous searches had come up empty-handed, says Brian Zimmerman, the curator for fishes at ZSL’s aquarium at London Zoo. “We thought it was likely the fish was extinct in the wild.”

But a few specialist hobbyists have raised these cichlids. In fact, ZSL had acquired a dozen fish in 2002 from a couple who had managed to breed them from wild-caught fish, which had been collected by French ichthyologist in the 1990s. It’s not always easy, or safe to do: A zoo in Berlin had tried to breed its pair of Mangarahara cichlids, but the male killed the female “when the courtship got out of hand,” Zimmerman says.

With only two fish known left in captivity, Zimmerman started contacting hobbyists in May about finding a female. No one had any more of the fish. A month later, though, he got an e-mail from a man in Madagascar who ran a hotel and raised tilapia in ponds. “I'm pretty sure we can find it,” the man wrote. After seeing a blurry photograph, Zimmerman arranged a trip to Madagascar in November.

Zimmerman and his colleagues searched for days near the Mangarahara River with no luck. But when they arrived in a village called Merotandrano, on a small tributary of the river, a fisherman gave him a Mangarahara cichlid that had been dead only a few days. Zimmerman hiked about 2 hours from Merotandrano to a few deep pools where villagers had set out traps. “They went charging into water,” Zimmerman recalls. “They were shouting: Joba mena!” That’s the local name for the fish, which means “red girl,” although in fact it’s the males that have trailing red edges on their fins.

The group trapped 18 fish and took them to the hotelier’s private ponds, about a 30-hour drive away. The next step is to determine if they will breed there. After that, Zimmerman hopes to move some fish into a forest reserve higher upstream from the pools.

“The discovery of Mangarahara cichlids in the wild could potentially open the door to captive breeding and restoring this species,” Thieme says. “It’s truly a ray of hope for the long-term survival of the species.”

Posted in Plants & Animals