Ciliated protozoa of a geothermal sulphur spring
Authors: Madoni, P.; Uluhogian, F.
Source: Hydrobiologia, Volume 353, Number 1-3, 19 September 1997 , pp. 161-170(10)
Abstract:The species richness and the dynamics of the ciliate communities were studied at three stations along a streamlet formed by water discharged from a geothermal sulphur spring. Altogether, 73 species were identified. Ciliate coenoses were composed primarily of freshwater forms, but they were numerically dominated by euryhaline species. The great fluctuation in both number of species and individuals observed along the streamlet were due to vigorous chemical changes in the physico-chemical characteristics of the water. These changes were caused mainly by the sulphide and salt gradient observed along the water course. The maximum value of sulphide was observed in August with 391 µM l^-1, and the highest conductivity value was observed in April with 18 mS cm^-1. The most characteristic and abundant species were small-sized bacterivorous scuticociliates which have a rapid ecological adaptability and whose tolerance limits to environmental changes are wide. Bacterivorous scuticociliates such as Cyclidium citrullus, C. glaucoma, Cinetochilum margaritaceum, and Uronema nigricans were numerically dominant when the thermal water contained the highest concentration of sulphide. The diversity index values changed sharply in time both inside and among sampling stations, indicating unstable communities which depended on highly fluctuating conditions.
Document Type: Regular Paper
Affiliations: Dipartimento di Scienze Ambientali, Universitàdi Parma, Via delle Scienze, 43100 Parma, Italy
Publication date: September 19, 1997