海角大神

There once was a small fish called 鈥渢equila splitfin鈥� or 鈥渮oogoneticus tequila鈥� 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聽鈥� but conserved in captivity聽鈥� to its native habitat.

Its success is now intertwined with the community鈥檚 identity and being touted internationally.

It began more than two decades ago in Teuchitl谩n, a town near the Tequila volcano. A half-dozen students, among them Omar Dom铆nguez, began to worry about the little fish that fit in the palm of a hand and had only ever been seen in the Teuchitl谩n river. It had vanished from local waters, apparently due to pollution, human activities, and the introduction of non-native species.

Mr. Dom铆nguez, now a researcher at the University of Michoac谩n, says that then only the elderly remembered the fish called 鈥済allito鈥� or 鈥渓ittle rooster鈥� 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, Mr. Dom铆nguez said.

The fish began reproducing in aquariums and within a few years Mr. Dom铆nguez and his colleagues gambled on reintroducing them to the Teuchitl谩n river. 鈥淭hey told us it was impossible, [that] when we returned them they were going to die.鈥�

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, not only from 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, 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.

鈥淲hen I started the environmental education program I thought they were going to turn a deaf ear to us ... and at first that happened,鈥� Mr. Dom铆nguez said.

But the conservationists succeeded with patience and years of puppet shows, games, and explanations about the ecological and health value of 鈥渮oogoneticus tequila鈥澛犫�� the fish help control mosquitos that spread dengue.

Some residents made up a nickname for the little fish: 鈥淶oogy.鈥� They made caricatures and formed the 鈥淩iver Guardians,鈥� a group mostly of children. They collect garbage, clean the river, and remove invasive plants.

Mr. Dom铆nguez said it is difficult to say if water quality is better because there is no previous data to compare, but the entire ecosystem has improved. The river is cleaner, there are fewer non-native species, and cattle are no longer permitted to drink in some areas.

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%. 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鈥檚 horse and the Arabian oryx are among successful examples. The Chester Zoo said Dec. 29 that the tequila splitfin had joined that small group.

鈥淭he project has been cited as an International Union for the Conservation of Nature (IUCN) case study for successful global reintroductions聽鈥� with recent scientific studies confirming the fish are thriving and already breeding in the river,鈥欌�� the zoo said in a statement.

鈥淭his is an important moment in the battle for species conservation,鈥� said Gerardo Garc铆a, the zoo鈥檚 curator of lower vertebrates and invertebrates.

The IUCN鈥檚 red list of threatened species lists the tequila splitfin as endangered. Mexico鈥檚 freshwater ecosystems are under pressure from pollution, over-extraction of water resources, and other factors. More than one-third of 536 species of freshwater fish that were assessed in the country are threatened with extinction, according to a 2020 report led by the IUCN and the ABQ BioPark in the United States.

Still, in Mexico, Mr. Dom铆nguez and his team are already beginning work on another fish that is considered extinct in the wild: the 鈥渟kiffia francesae.鈥� The Golden Skiffia could some day join 鈥淶oogy鈥� in the Teuchitl谩n river.

This story was reported by The Associated Press.聽