Sensitivity of Different Scenedesmus Strains to the Endoparasitic Microorganism Amoeboaphelidium

The sensitivity of 142 Scenedesmus cultures to four different strains of the endoparasitic microorganism Amoeboaphelidium was investigated. The sensitivity or resistance to the different parasite strains was stable and characteristic for any given culture or clone, but not for a species in general. This character can be used for the description and differentiation of Scenedesmus cultures.Even among Scenedesmus strains isolated from a single locality, different sensitivity types can be found, indicating appreciable physiological diversity.Not all theoretically possible culture types were found. In the collection examined, the most abundant type comprised Scenedesmus cultures resistant to strain X-1 but sensitive to some others. Some combinations were not observed at all. Sensitivity to different parasites may be determined by different combinations of genetic characters.