Fish inventories in the Magdalena River basin (Colombia) as a tool for their conservation management

The inventories of fish fauna through the elevation interval in Andean rivers are tools to generate conservation strategies in the region, therefore the completeness of these inventories is essential to take sound decisions. The material deposited in five biological collections, and that collected in three explorations carried out in years 2014, 2015, and 2016 in 64 localities that drain into the Magdalena River basin was examined. The richness consisted of 115 fish species. We found that the rate of decrease in the number of species was 54 per 900 m. of elevation. Using a species prediction model, we showed that the total number of species was only recorded in the 300-600 m. interval and in the high Andean zone. This suggests that a greater sampling effort is required to obtain a sufficient representation of the estimated real richness for each the elevation intervals evaluated. Additionally, different threats on the water bodies were detected in the elevation intervals, such as extensive cattle ranching and agriculture, unregulated mineral extraction, hydroelectric power generation, as well as the use of fish as a protein resource, including the farming of introduced species. As the modification of habitats continues without adequate planning, there is a risk of affecting the richness and distribution of species in the basin, therefore, it is important to know their ecological aspects, which will allow to propose recommendations and find opportunities for their conservation.