Prof. H.-D. Görtz and his contribution to our knowledge of protozoan symbiosis.

Since the beginning of the 1980s, the Paramecium-Holospora system has become an important model and a subject of international scientific cooperation in symbiosis studies, established by Prof. H.-D. Görtz. In the article, a brief sketch of the scientist's life, his areas of interest, expertise and his contribution to our knowledge of protozoan symbiosis are discussed.