Baños del Azufre Habitat Use

During our 2014 field season, with financial support from the Mohammad bin Zayed Species Conservation Fund, we conducted extensive sampling of the Baños del Azufre spring complex near Teapa, Tabasco. The goal of the project was to establish critical habitat for two endangered, endemic species, Gambusia eurystoma and Poecilia sulphuraria. Sampling 30 localities along more than 2km of stream we characterized physical and chemical properties associated with each species’ density and body size of P. sulphuraria. Our results showed that Gambusia density was best predicted by stream flow and substrate size, but Poecilia were not associated with any putative physical nor chemical predictors. However, body size of Poecilia was negatively correlated with H₂S concentrations suggesting a cost to living near higher concentration springs.