MEXICAN FISH EXTINCT IN WILD SUCCESSFULLY RETURNED TO NATURE
There once was a small fish called “tequila splitfin” or “zoogoneticus tequila” that swam in a river in western Mexico, but disappeared in the 1990s. Scientists and residents, however, have achieved the return of a species extinct in nature — but conserved in captivity — to its native habitat.
Its success is now intertwined with the community’s identity and being touted internationally.
It began more than two decades ago in Teuchitlan, a town near the Tequila volcano. A half-dozen students, among them Omar Dominguez, began to worry about the little fish that fit in the palm of a hand and had only ever been seen in the Teuchitlan river. It had vanished from local waters, apparently due to pollution, human activities and the introduction of non-native species.
Dominguez, now a 47year-old researcher at the University of Michoacan, says that then only the elderly remembered the fish called “gallito” or “little rooster” because of its orange tail.
In 1998, conservationists from the Chester Zoo in England and other European institutions arrived to help set up a laboratory for conserving Mexican fish. They brought several pairs of tequila splitfin fish from the aquariums of collectors, Dominguez said.
The fish began reproducing in aquariums, and within a few years Dominguez and his colleagues gambled on reintroducing them to the Teuchitlan river. “They told us it was impossible, (that) when we returned them they were going to die.”
So they looked for options. They built an artificial pond for a semi-captivity stage, and in 2012 they put 40 pairs there.
Two years later, there were some 10,000 fish. The result guaranteed funding, from not only the Chester Zoo but also a dozen organizations from Europe, the United States and the United Arab Emirates, to move the experiment to the river.
There they studied parasites, microorganisms in the water, the interaction with predators and competition with other fish, and then introduced the fish in floating cages.
The goal was to re-establish the fragile equilibrium. For that part, the key was not so much the scientists as the local residents.
“When I started the environmental education program I thought they were going to turn a deaf ear to us, and at first that happened,” Dominguez said.
But the conservationists succeeded with patience and years of puppet shows, games and explanations about the ecological and health value of “zoogoneticus tequila” — the fish help control mosquitoes that spread dengue.
The fish rapidly multiplied inside their floating cages. Then they were marked so they could be followed and set free. It was late 2017 and in six months the population increased 55 percent. Last month, the fish had expanded to another part of the river.
The reintroduction into nature of species that were extinct in the wild is complex and time-consuming. Przewalski’s horse and the Arabian oryx are among successful examples. The Chester Zoo said Dec. 29 that the tequila splitfin had joined that small group.