Chirostoma aculeatum

Chirostoma aculeatum, commonly known as the spiny silverside or charal espinoso, is a freshwater fish species endemic to the high-altitude lakes of central Mexico's Trans-Mexican Volcanic Belt. This small, elongated fish typically inhabits shallow, vegetated areas of lakes and is characterized by its silvery appearance and distinctive spiny dorsal fin. The species was historically found in several lake systems including Lake Pátzcuaro and other water bodies in Michoacán state. Chirostoma aculeatum faces severe population declines that have led to its classification as Critically Endangered by the IUCN. The primary threats include habitat degradation from water pollution, agricultural runoff, and urban development around lake systems. Introduction of non-native fish species has created additional pressure through competition and predation. Water level fluctuations due to extraction for agricultural and municipal use have further reduced available habitat. Climate change impacts, including altered precipitation patterns and increased temperatures, compound these existing stressors. The species' restricted range makes it particularly vulnerable to local environmental changes. Conservation efforts have been limited, though some local initiatives focus on habitat restoration and water quality improvement in key lake systems. Research programs aim to better understand the species' ecology and population status. The critically endangered status highlights the urgent need for comprehensive conservation strategies to prevent extinction of this endemic Mexican fish species.