Changes in diversity and distribution of native fish with the presence of two invasive species in the Atacames river, Ecuador.
The interpretation of biological diversity can be very complex, since there is a dynamic based on the origin and diversification of species, as well as on anthropic effects, such as the introduction of invasive species, the consequence of which can lead to extinction. local native species. The objective of this work was to analyze the temporal variation (2012 and 2017), both in composition and distribution of the ichthyofauna along the Atacames River, northwestern Ecuador. In 2012, the following were recorded: (1) the presence of Astyanax ruberrimus, which became locally extinct by 2017; and (2) the presence of tilapia (Orechromis niloticus) as the only introduced species to which the guppy (Poecilia gillii) for 2017. Additionally, the increase in human activities led to an arrangement in the diversity, abundance and distribution of fish along the riverbed, which also determined that some species dispersed towards the upper zone of the basin.