Anaerobic ciliates from a sulphide-rich solution lake in Spain

We have examined and quantified the anaerobic ciliates living in the hypolimnion of a 14 m deep sulphide-rich (up to 0.73 mM) solution lake in Spain. At least seven ciliate species were found, numbering up to 50 ml-1 in total and reaching maximum abundance close to the sediment. Caenomorpha medusula, Lacrymaria elegans, L. sapropelica and Lagynus sp. were the most abundant species. Their vertical distributions were not related to the sulphide profile. Most ciliates were dependent on the sedimentation of cryptomonads, photosynthetic bacteria (especially Chromatium and Oscillatoria) and other bacteria from their sites of production in closely-juxtaposed mid-water plates. All anaerobic ciliate…