RATES OF GROWTH,RESPIRATION AND PHOTOSYNTHESIS OF UNICELLULAR ALGAE AS RELATED TO CELL SIZE—A REVIEW1,2

The decline of growth rate with increasing species size of unicellular algae grown under uniform conditions is quantified by applying to published data the equation, growth, (cell · time)^?1= a (cell carbon)^b where a and b are coefficients. The degree of size-dependence might be highest under optimal conditions of growth where b is 0.75. Respiration rate is shown to decline with size in the same manner. It is postulated that gross photosynthesis and processes underlying growth are similarly size-dependent. Growth, efficiency (net over gross photosynthesis) cannot be shown to be size-dependent. Cell size, expressed as carbon, is proposed as a scaling factor in comparative algal physiology.