<div>Symbiodinium cell counts were determined with a Neubauer haemocytometer (Reichert). Five separate squares of 0.1µl volume within each of two or four separate chambers were counted per sample. To avoid concentration of cells by gravity seen in conical pipette tips, samples were loaded using a cylindrical Pasteur pipette. Coral skeletal surface areas were estimated using by paraffin wax dipping (Stimson and Kinzie III, 1991), using a first wax dip to seal the skeleton and a second wax dip to determine surface area.<br></div>