Efficiency of Filter Feeding in Two Species of Tetrahymena*

Abstract
SYNOPSIS. Rates of removal of suspended India ink particles from the surrounding medium by 2 ciliates, Tetrahymena pyriformis strain GL and Tetrahymena vorax strain V2S, have been measured. It is evident from the results that the food vacuoles concentrate the suspended particles, clearing a volume of the surrounding suspension fluid 500 × greater than the total volume of food vacuoles made during the same period of time.