Subterranean Fishes of the World

4807

2018

Teoria y Praxis

49-68

25

Karstic water bodies represent the most relevant limnologic feature of the Yucatan Peninsula, Mexico. These systems harbor endemic species and are the main regional epigean source of freshwater. In this work, the morphometry, basic limnological features, and the zooplankton and fish fauna of five aquatic karstic systems from the central zone of Quintana Roo State, Mexico (in the heart of the Zona Maya) were surveyed. The possible relation between species richness and morphometric features was tried to be established. Overall, 79 taxa were found, 64 belong to zooplankton, and 15 to nekton. All studied systems were oligotrophic, with high transparency, and low nutrients and chlorophyll a concentration, thus differing from other water bodies in central Mexico. The two different types of karstic systems studied were the typical “cenote”, and the “aguada”. Both showed differences in biological, physical, and chemical variables. A one-way ANOVA test demonstrated significative differences in nutrients (nitrates, F = 61.52, p<0.001; nitrites, F=7.361, p<0.001) and conductivity (F = 497.491, p<0.001) among systems. A simple concordance cluster analysis showed that species richness and community composition were also different between these two types of aquatic systems. In contrast to previous results found in central and southeastern Mexico, no correlation between species richness and morphometric parameters (area and shoreline development) were found. In the south-central region of the Yucatan Peninsula, the aquatic karstic systems are poorly known (physically, chemically and biologically). In fact, this is the first approach to understand the limnology and the relation between species richness and morphometric variables of the sinkholes from the region. Key words: cenotes, freshwater, karst, aquatic biodiversity, limnology.

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