Abstract

From a hypothesis about nitrogen-limited status of zooxanthellae in corals, anequation describing nitrogen balance for algae living in host tissue was developed.Using published experimental data, some characteristics of nitrogen exchange forzooxanthellae cells were calculated. The calculations show that zooxanthellae obtainthe main part of nitrogen (65-70%) from the surrounding water by ammoniumdiffusion. The N: C ratio in substances translocated from alga to host is about 0, 015, and this value is according with performances about participation of carbohydratesand lipids in translocation process. The possible influence of light and particulatefood on the zooxanthellae density in corals was quantitatively estimated.