CR

Toluca Silverside

Chirostoma riojai

Declining

Overview

A detailed profile for this species is sourced from the IUCN Red List of Threatened Species as assessments become available.

Chirostoma riojai faces severe threats from water extraction and diversion that has dramatically reduced water levels in its native lake system. Agricultural runoff and urban pollution have degraded water quality, while introduced species compete for resources and alter the ecosystem dynamics. The species' extremely restricted range makes it particularly vulnerable to any environmental changes in its single lake habitat.

Threat summary

Habitat

This endemic silverside fish inhabits the shallow, alkaline waters of Lake Pátzcuaro in Michoacán, Mexico. It typically occurs in nearshore areas with aquatic vegetation where it feeds on small invertebrates and algae.

FRESHWATER· major

Conservation measures underway

Ex-situ conservation

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Frequently asked questions

Why is Toluca Silverside classified as Critically Endangered?
Toluca Silverside is classified as Critically Endangered — facing an extremely high risk of extinction in the wild — because population sizes are very small, declining sharply, or restricted to a tiny range. Chirostoma riojai faces severe threats from water extraction and diversion that has dramatically reduced water levels in its native lake system. Agricultural runoff and urban pollution have degraded water quality, while introduced species compete for resources and alter the ecosystem dynamics. The species' extremely restricted range makes it particularly vulnerable to any environmental changes in its single lake habitat.
Where does Toluca Silverside live?
Toluca Silverside occurs in Mexico. Country-level distribution data is sourced from the IUCN Red List and cross-referenced with GBIF occurrences.
What are the main threats to Toluca Silverside?
The main threats to Toluca Silverside are 1.1, 2.1, 5.4, and 7.2. The full IUCN-classified threat record for this species is detailed on the species page.

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