Allotoca meeki

Allotoca meeki is a small freshwater fish endemic to the Mesa Central region of Mexico, specifically found in the upper Lerma River basin. This species belongs to the family Goodeidae, a group of livebearing fish native to Mexico's highland waters. The fish typically inhabits shallow areas of rivers and streams with moderate flow rates and rocky or sandy substrates.

Allotoca meeki is characterized by its small size and the typical body plan of goodeid fish, with males displaying more pronounced coloration during breeding periods. The species faces severe population declines that have led to its classification as Critically Endangered by the IUCN. Primary threats include habitat degradation from agricultural runoff, urban development, and water extraction for human use.

The introduction of non-native fish species has also contributed to population pressure through competition and predation. Water pollution from industrial and domestic sources has further compromised the quality of remaining habitat. The species' restricted range makes it particularly vulnerable to local environmental changes.

Conservation efforts have focused on habitat protection and water quality improvement in key areas of the Lerma River system. Research initiatives aim to better understand the species' ecological requirements and population dynamics. Ex-situ conservation programs have been established to maintain breeding populations in controlled environments as a safeguard against extinction.

Collaboration between Mexican institutions and international conservation organizations continues to support recovery efforts for this endemic species.

This species inhabits shallow areas of rivers and streams in Mexico's Mesa Central region, particularly in the upper Lerma River basin. It prefers waters with moderate flow rates and rocky or sandy substrates.