Ictiofauna de sistemas cárstico-palustres con impacto antrópico: los petenes de Campeche, México

ichthyofauna of karstic wetlands under anthropic impact: the "petenes" of campeche, mexico. "petenes" are small springs and associated streams that drain into wetlands near the coast in karstic areas. we studied composition, distribution, and abundance of the ichthyofauna in los petenes region (northwest campeche). two petenes displaying different degrees and types of anthropic impact were selected, hampolol and el remate. hampolol has a smaller area but a longer derived stream; it is located within a protected area, but has been invaded by tilapia. el remate is a popular spa, with no tilapia; it has a larger area but a shorter derived stream. at each "petén", several sites in the main spring, the associated stream, and secondary (temporary) springs were sampled in the rainy and dry seasons. fishing gear was variable (throw net, gill net, small and large seine nets), but effort was uniform. we recorded temperature, dissolved oxygen, salinity, and depth at each site and season; also, we noted the different types and intensities of anthropic impact (channelization, presence of exotic species, recreational use, etc.) at each petén. we compared the petenes in terms of their environmental quality and fish fauna (composition, distribution, abundance, biomass); we also tested for effects of season and site within each petén. the study found 27 species of fishes, included in 18 genera and eight families, 24 species in hampolol and 20 in el remate. the geographical range of ？cichlasoma？ salvini, rivulus tenuis, phallichthys fairweatheri, xiphophorus hellerii, and x. maculatus is extended. the dominant species in both seasons was astyanax (probable hybrids a. aeneus × altior at hampolol, pure a. altior at el remate), which contributed most of the abundance and biomass, together with vieja synspila and poecilia velifera. a significantly greater overall diversity (h？n=3.31) was recorded in hampolol compared to el remate (h？n=2.10). cluster analysis of sites by species presence