Endangered mexcalpique is breeding again in restored Lake Texcoco wetlands

An endangered fish found only in the Valley of Mexico is reproducing again at Lake Texcoco, offering evidence that its restored waters are developing into a functioning wetland ecosystem.

The mexcalpique, a small live-bearing fish, had disappeared from the former airport project area after extensive drainage and construction. Some populations survived in nearby waters, enabling Mexico’s National Commission of Natural Protected Areas to return the species to the lake through three releases of about 100 fish each, beginning two years ago.

Officials now report abundant populations and successful breeding. The fish has been detected across more than 1,200 hectares of the lake’s flooded habitat, including waters occupying the footprint of the cancelled airport. Researchers from the National Autonomous University of Mexico are monitoring water quality, algae, insects and other animals to track the broader ecological recovery.

The former terminal excavation has been turned into a permanent body of water. Officials say its construction material now acts as a large biofilter as water enters the protected area. Although the water is naturally turbid, monitoring has found oxygen levels capable of supporting aquatic life.

Restoration teams are also assessing whether parts of the lake could eventually support highland axolotls and freshwater crayfish. Researchers caution that any reintroduction would require further evidence of suitable water, food and breeding habitat.