60 years ago, the residents of Xochimilcothe lake area south of Mexico CityThey could grab Ajolotes With the hand. Now seeing this peculiar amphibian freedom that looks like a mixture of salamandra and dragon is almost impossible, but scientists follow the track through their DNA.
Academics of the National Autonomous University of Mexico (UNAM) have found their genetic trail in this capital neighborhood formed by canals and land rafts called “chinampas” – in some of which are still cultivated to pre -Hispanic way – And that shows that there are still sajolotes in wildlife, although its situation is critical.
They used a technique that will help the update of the census of these amphibians that since 2019 have been in the red list of threatened species of the International Union for the Conservation of Nature.
“We all release DNA to our passage through the world and that can be captured filtering the air or water”explained to The Associated Press the biologist Luis Zambrano, of the Ecology Restoration Laboratory of the UNAM.
And that is just they did.
They collected water from the Xochimilco channels, leaked and took what is called “Environmental DNA”, that is, genetic particles of animals and plants in contact with that water that they compared with those already existing in a genetic library prepared a few years ago by British scientists, said Esther Quintero, international-Mexico conservation, an NGO that joined the Zambrano project in 2023 supports.
The academics used this technique in 53 points of Xochimilco, ten within “refuge areas” – channels that have, among other things, filters to keep the water clean – and 43 points outside of them. The DNA of the ajolotes was in the shelters and also at an out of them.
“It’s very little, a single point”Zambrano acknowledged. But he said that he shows that Some specimens resist in corners that have managed to dodge the growing environmental degradation of the channels and the contamination of their water.
Until now, only one third of Xochimilco has been tracked, both with the environmental DNA technique and with the traditional network, but the project will continue from September and scientists are confident in having an updated census in early 2026, which will predictably confirm the drastic decrease in specimens that began decades ago: an estimated 6,000 per square kilometer in 1998, it passed only 36 in 2014, the last year of the last census.
But not everything is bad news. Zambrano emphasized that his team has also shown that conservation works and that preserving this species “has multiple benefits”: contributes to water quality and the amount of pollinators in the area. And having a preserved Xochimilco helps a better use of water in Mexico City, to have a greater source of food and cushion the temperature of the city.
To achieve this, according to Zambrano, the work of academics and neighbors is not only necessary – sometimes with ingenious initiatives to finance such as adopting an axolot – and the growing interest of society (its brain regeneration capacity is studied and its image is in memories, video games and tickets).
What urges, said the biológo, is that the authorities get involved with public policies that do not allow certain activities, such as discounts, spas or soccer fields in the Chinampas, and promote others of environmental recovery such as chinampera production, guaranteeing those peasants dignified income and quality of life.
“Aagle is reproduced a lot because it puts many eggs … you can easily recover and we already know how”Zambrano said. It is put to the work and a large scale.