Tequila fish: the curious case of the “extinct” fish that came to life in the rivers of Mexico

A small miracle returns to cross the rivers of the southwest of Mexico.

The Tequila fish, “disappeared” since 2003, has been returned to nature after being declared extinct, according to the BBC.

“It’s just a little fish, not very colorful, there isn’t much interest in terms of global conservation,” explains Gerardo García, a conservationist at Chester Zoo in the UK.

However, the program that has reintroduced the fish is an example of how freshwater species and ecosystems can be saved, one of the most threatened on Earth, according to the International Union for Conservation of Nature (IUCN).

And in the process, the local community, in Jalisco, Mexico, has been crucial.

The success of the operation has had a lot to do with the people living near the Tequila fish release site, they are playing a key role in monitoring the water quality of the rivers and lakes.

“This is the first time that an extinct species of fish has been successfully reintroduced in Mexico, so it is a true milestone for conservation,” said Omar Domínguez, from the Universidad Michoacana de México, whose team led the experiment.

“We could not have done this without the local people, they are the ones who allow conservation to be long-term,” he added.

How was a fish that seemed extinct reborn?

A decades-long partnership between conservationists in Mexico and the UK has allowed 1,500 fish to be released, already expanding through the river system.

But the project dates back to 1998. That’s when it all started.

That year scientists from the Aquatic Biology Unit of the Michoacana University of Mexico received five pairs of fish sent from the Chester Zoo, in the United Kingdom.

These 10 fish founded a new colony in the university laboratory, which the experts maintained and expanded for the next 15 years.

Before being returned to the river, 40 males and 40 females from the colony were released into large man-made ponds at the university.

This step was essential in training captive-bred fish to live in a wild environment with inconsistent food resources, potential competitors, parasites, and predators.

After four years, it was estimated that this population increased to 10,000 individuals and became the source of reintroduction to the wild.

“This shows,” says Gerardo García, “that animals can readjust to nature when they are reintroduced at the right time and in the right environments.”