Dry to wet weight biomass conversion constant for Tetrahymena elliotti (Ciliophora, Protozoa)

The wet and dry weights of both axenic and monoxenic cultures of the ciliate Tetrahymena were determined directly. These estimates are dependent upon the method of volume determination. Assuming a prolate spheroidal shape for the ciliate, we calculate a mean wet weight of 0.4157±0.0713 pg μm^-3 and a mean dry weight of 0.2793±0.0652 pg μm^-3. Using electronic cell sizing, our estimates are 0.7869±0.1659 pg μm^-3 and 0.5239±0.1101 pg μm^-3, respectively. Independent of the method of volume determination, we estimate a mean biomass conversion ratio (dry weight/wet weight) of 0.59±0.08.