Distribution and habitat suitability of andean climbing catfish in the Napo River Basin, Ecuador

Astroblepidae face numerous threats in Ecuador, and their range is thought to be decreasing in most basins due to urban development, agriculture, oil and mineral extraction, dams, and introduction of exotic species. In the Napo River Basin, one of the largest and most-diverse river basins in Ecuador, Astroblepus vaillanti is also potentially being displaced by rainbow trout (Onchorynchus mykiss) introductions at higher altitudes, yet no published information exists on the habitat requirements and distribution of the species. In this study, we developed species–habitat relationships for a suite of physico-chemical variables and compared abundances of A. vaillanti in streams heavily impacted by agriculture and less impacted streams. Interestingly, we found significantly higher abundances of A. vaillanti in heavily impacted streams. We also found that A. vaillanti abundance was positively related to stream temperature, whereas the inverse was true for rainbow trout. Our study highlights the need for further study to understand the habitat requirements and diet of A. vaillanti as well as the impacts of rainbow trout on the species to inform conservation efforts of the species.