Ciliated protozoa and saprobical evaluation of water quality in the Taro River (northern Italy)

Ciliate protozoans were collected at three stations during one year from A.-ater-sediment interface of a branch located in the hyporhithron section of the River Taro (northern Italy). A total of 89 species of ciliates belonging to 59 genera were found, of which 26 were bacterivorous, 31 algivorous, 21 omnivorous and 11 carnivorous. Their distribution varied both along the river and in time. Community structures were analysed using some statistical methods, and this allowed the determination of similarity among stations and between species and stations. The ciliate communities at the three stations proved quite similar. A saprobic evaluation of the section of the river was made using the taxocenoses observed, and the results showed that the microfauna was composed of beta-mesosaprobic species typical of watercourses with moderate organic load content.