||Ciliate Paramecium caudatum
||Katsu-Kimura Y, Nakaya F, Baba SA, Mogami Y. Substantial energy expenditure for locomotion in ciliates verified by means of simultaneous measurement of oxygen consumption rate and swimming speed. J Exp Biol. 2009 Jun212(Pt 12):1819-24. doi: 10.1242/jeb.028894. p.1820 left column 2nd paragraphPubMed ID19482999
||"In this paper, [researchers] will present the energy expenditure of
Paramecium in close relation to its swimming activity. For this
purpose, paramecia were confined in a small volume of the chamber
(<1 ml) and the oxygen consumption rate and the swimming speed
were measured simultaneously from the same specimens. Oxygen
consumption was measured by means of an optic fluorescence
oxygen sensor (Okubo et al., 2008). Because this sensor has proved
not to alter the amount of dissolved oxygen unlike oxygen electrodes,
which consume a substantial amount of oxygen during the
measurement procedure, it is ideal for measuring the oxygen
concentration in a small volume of a sample. Swimming speed was measured from the recording obtained by the optical slice method
(Kato et al., 2003)."
||"[Researchers'] measurements revealed a linear relationship between the rate
of the oxygen consumption and the speed of freely swimming Paramecium. By extrapolating from the regression line between oxygen consumption rate and swimming speed, [they] could estimate that the energy expenditure of the cell in the ‘non-motile’ state is about a quarter of the total energy consumed by the cell when swimming. This indicates that Paramecium uses a large amount (ca.70%) of energy for swimming."