Respiration rates and biovolumes of common benthic Foraminifera (Protozoa)

Abstract

The respiration rates of five genera of benthic Foraminifera were determined by Cartesian diver microrespirometry. Across all genera studied, the rate averaged 11·3×10 −3 μl O 2 individual −1 h −1 at 10°C. Estimates of foraminiferal mean biovolumes ranged from 0·66 to 6·54×10 6 μm 3 , giving an overall mean volume-specific respiration rate of 7·36 × 10 −9 μl O 2 h −1 μm −3 . For non-symbiont-bearing Foraminifera, in general, volume-specific rates (log μl O 2 h −1 μm 3 ) are best described by the equation, −0·98 × (log cell biovolume, μm 3 )−2·01. The respiration results show that these benthic Foraminifera respire some ten times more rapidly than naked amoebae of equivalent size. The combination of high respiratory rates and the often large standing stocks of Foraminifera encountered, suggests that these organisms may contribute significantly to total microbial benthic respiration.