Non-native freshwater fishes in Guatemala, northern Central America: introduction sources, distribution, history, and conservation consequences

Non-native freshwater fishes have been introduced to Guatemalan freshwater ecosystems since the beginning of the last century without prior risk assessment or subsequent evaluation of their impacts. We synthesized historical records, and distributional data from a literature review, online databases and museum records of non-native freshwater fishes in Guatemala. We found records for 22 nonnative freshwater fishes with the oldest records dating back to 1926. Non-native freshwater fishes were recorded in 64% of the river sub-basins in Guatemala and we identified that at least 12 species have established populations. The Jaguar guapote (Parachromis managuensis) and Tilapias (Oreochromis spp.) are the most widespread non-native fishes. The species of non-native freshwater fishes introduced indicates that they are human selected (e.g., for farming purposes). Our work shows that aquaculture has been the major driver of introductions in the country, but aquarium release has become an important source in the last 20 years. Given the potential impact of non-native freshwater fishes on native fauna and ecosystems, we highlight an urgent need to assess their ecological effects, as well as to establish a fish fauna monitoring program in Guatemala to detect new introductions. Government and nongovernmental agencies should promote the use of native species to supply fish demands in alignment with environmental policies and the objectives of the fishing agency in Guatemala.

Automated summary

Non-native freshwater fishes have been introduced to Guatemala's freshwater ecosystems since the early 20th century without prior risk assessment. Records show that non-native freshwater fishes have been found in 64% of the river sub-basins in Guatemala, with at least 12 species establishing populations. Aquaculture has been the main driver of introductions, but aquarium release has also become an important source in recent years. Urgent assessment of the ecological effects of non-native freshwater fishes and establishment of a fish fauna monitoring program are needed to detect new introductions. It is recommended that native species be promoted to meet fish demands in alignment with environmental policies and the objectives of the fishing agency in Guatemala.