Target Species Selection And Design Of Fish Habitat Suitability Curves In The Ayuquila-Armeria River, Western Mexico

The implementation of hydroecological models requires an understanding of the biological attributes and habitat requirements of the local stream fauna. We describe a procedure for selecting target (fish) species and calculating habitat fitness curves based on depth and velocity and substrate type data in the Ayuquila-Armeria river in central-western Mexico. The selected target species wereSicydium multipunctatum,Agonostomus monticolaandAllodontichthys zonistius, and selection of these species was based on their endemism, vulnerability and sensitivity. Eighty-four samples from nine sites monitored over 14 years were used to calculate category III univariate curves. The suitability curves proposed for each target species describe their habitat suitability values in terms of depth (m), velocity (m s(-1)) and substrate type (mm). These curves allow the construction of eco-hydraulic models necessary to define the minimum ecological flow in the Ayuquila-Armeria river.