diatoms of calcareous tropical springs in the central region of mexico

Abstract

57 species of diatoms (Bacillariophyceae) were found in four calcareous springs in the central region of Mexico. 6 belong to Centrales and 51 belong to Pennales. Information for each species includes: general ecological characteristics, salinity, saprobity, pH, nutrients, temperature and known geographical distribution in Mexico. With respect to temperature, 24 of 31 species reported in the literature coincided with our values (20-27 degrees C, mesothermal or euthermal). 37 of 41 species with published pH data have been reported as alkaliphilous, alkalibiontic or indifferent to pH, corresponding to conditions in the Huasteca. With respect to salinity 23 of the 36 species are reported from low salinity habitats (oligohalobous or halophilous). Lastly, with respect saprobity, 38 species with reports in the literature has been found in habitats with low concentrations of organic matter (mesosaprobic, oligosaprobic, saproxenous and saprophobic). The importance of these characteristics to use the species as ecological indicators is discussed.