Invasive cichlids(Teleostei:Cichliformes)in the Amacuzac River,Mexico:Implications for the behavioral ecology of the native Mexican mojarra Amphilophus istlanus

The introduction of species is a leading cause of biodiversity loss and habitat alteration.Several species have invaded Mexican freshwater ecosystems,adversely affecting native fishes.Specifically,in the Amacuzac River of the Balsas Basin(Central Mexico),at least four non-native cichlids have been recorded:tilapia Oreochromis sp.,convict cichlid Amatitlania nigrofasciata,spotcheek cichlid Thorichthys maculipinnis,and green terror Andinoacara rivulatus.These species co-occur with the Mexican mojarra Amphilophus istlanus,the only native cichlid in the Basin.Invasive cichlids compete for resources such as shelter and food,and prey on offspring of the Mexican mojarra.In the presence of invasive cichlids,the costs and risks of foraging and finding available shelter increase for the native cichlid.Predation pressure from invasive cichlid fishes on the Mexican mojarra increases the time invested by parents in caring for offspring and their stress levels,potentially contributing to Mexican mojarra population declines.Here,we gathered the best evidence available to discuss some mechanisms and consequences of such co-occurrences in relation to reproductive behaviors,parental care,competition for resources,and dominance hierarchy,and how the four invasive cichlids have negatively affected the Mexican mojarra.