MEPS prepress abstract   -  DOI: https://doi.org/10.3354/meps14684

ABSTRACT: Sponges pump large volumes of water to gain nutrition from a dilute suspension of food particles and DOM. Our review of the literature shows pumping power P_p ranging from 0.85% up to 28% of the total metabolic respiration rate R_tot, where the pumping power, P_p = pumping rate × pump pressure, is the energy per unit time transferred to the water flow. As shown, some published values of pumping costs are high while others are low due to incorrect estimates of some pressure losses in the aquiferous system of sponges. However, as improved descriptions of detailed structures and function of especially the filter-apparatus of the choanocytes have become available, our corrected values for pressure losses show the respiration-specific pumping costs of P_p/R_tot. = 1.3 to 12.7%. The stated pumping cost is based on the minimal (theoretical) pump power delivered to the water, which excludes a mechanical efficiency of pump action and a metabolic efficiency that expresses the fraction of total metabolism that is devoted to driving the pump action, considerations that should be included in future studies.