Biomechanics of water-pumping by Chaetopterus variopedatus Renier: Kinetics and hydrodynamics

1. The activities of the three water-pumping segments of Chaetopterus variopedatus are correlated in detail with the fluctuations in water flow through the tube-house. 2. The qualitative performance and design features of the worm's pumping mechanism are compared to those of mechanical reciprocating pumps. 3. Quantitative data on volume flow rate, stroke rate, discharge pressure, and oxygen consumption yield estimates of power output (1.5 X 10(-5) Joules/sec) and aerobic efficiency (0.5%). 4. In its natural habitat, Chaetopterus does no lifting work, but rather functions solely as a transfer pump. 5. Calculations show that, of the work accomplished by Chaetopterus during pumping, 95% is devoted to overcoming inertial resistance.