Abstract
Commonly known as suckermouth armored catfishes or pleco, Pterygoplichthys spp. are a group of invasive fishes that are widely distributed in several countries, including Mexico. This paper reports the first records of suckermouth armored catfishes in the Candelaria River, thereby expanding its distribution within the Yucatan Peninsula. Fifteen individuals were collected from three sites in the upper and middle parts of the basin. They represented two phenotypically distinct species of catfishes: (vermiculate) Pterygoplichthys disjunctivus (Weber, 1991) and (spotted) Pterygoplichthys pardalis (Castelnau, 1855). Adults and juveniles were caught in lotic ecosystems in 2023 during the dry and rainy seasons. Results suggest that the invasive process of the Candelaria River is linked to the San Pedro River upper basin, in El Petén, Guatemala, through floodings enhanced by hurricanes, allowing these species to disperse. These records highlight the importance of connectivity between adjacent watersheds for the dispersal and expansion of these invasive fishes, mainly from rivers neighboring Guatemala. However, further research is necessary to explore the dynamics and connectivity between aquatic ecosystems and the possible mechanisms that promote the invasion of these fishes in this region.