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 11·3×10−3μl O2individual−1h−1at 10°C. Estimates of foraminiferal mean biovolumes ranged from 0·66 to 6·54×106μm3, giving an overall mean volume-specific respiration rate of 7·36 × 10−9μl O2h−1μm−3. For non-symbiont-bearing Foraminifera, in general, volume-specific rates (log μl O2h−1μm3) are best described by the equation, −0·98 × (log cell biovolume, μm3)−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.