Mayamaea sardiniensis sp. nov. (Bacillariophyceae), a new species from a thermo-mineral spring in Sardinia, Italy

Mayamaea sardiniensis sp. nov. is described from periphytic diatom samples collected in a small thermo-mineral spring in Sardinia (Italy), based on a morphological approach. In light and scanning electron microscopy, the species revealed the presence of typical features of the genus Mayamaea, as reported in the original diagnosis, including elliptical to oval valve outline, broadly rounded apices, and uniseriate striae composed of round areolae occluded by external hymenes. Mayamaea sardiniensis shares strong similarities with M. cavernicola and M. petersenii. Differences with these species mainly include shape of the valve, pattern and density of striae. The presence of M. sardiniensis in the type locality seems to be linked to the ecotonal nature of the spring environment.