Abstract
The activities of the 3 water-pumping segments of C. variopedatus are correlated in detail with fluctuations in water flow through the tube-house. The qualitative performance and design features of the worm''s pumping mechanism are compared to those of mechanical reciprocating pumps. Quantitative data on volume flow rate, stroke rate, discharge pressure, and O2 consumption yield estimates of power output (1.5 .times. 10-5 J/s) and aerobic efficiency (0.5%). In its natural habitat Chaetopterus does no lifting work, but rather functions solely as a transfer pump. Of the work accomplished by Chaetopterus during pumping, 95% is devoted to overcoming inertial resistance.