Some observations on Zoochlorella conductrix symbiosis with Hydra viridissima.

Abstract

The proposal for this project was to secure collections of Zoochlorella infected Hydra and Vorticella species from Refrigerator Pond and Douglas Lake plankton. They were to be separated and isolated as much as possible from the mixed collections and then various samples placed in continuous dark. It was thought that periodic examination of the dark samples when compared to samples allowed ambient light would show visible differences. I assumed that Zoochlorella would be a photoheterotroph that required something besides light, and that is supplied by its hosts, and the hosts would not tolerate the algal's presence unless they rely on algal products as well. My hypothesis was that the symbiotic relationship was a mutualistic one and the symbiotic hosts kept in the dark would not do as well as their corresponding controls.