|Filter-feeding in the polychaete Nereis diversicolor: growth and bioenergetics|
Vedel, A.; Riisgård, H.U. (1993). Filter-feeding in the polychaete Nereis diversicolor: growth and bioenergetics. Mar. Ecol. Prog. Ser. 100: 145-152
In: Marine Ecology Progress Series. Inter-Research: Oldendorf/Luhe. ISSN 0171-8630, more
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Field studies in Danish waters (Odense Fjord and Fyns Hoved) showed that the facultatively filter-feeding polychaete Nereis diversicolor, kept in U-shaped glass tubes elevated 15 cm above the bottom, is able to grow on phytoplankton as the sole food source. The greatest increase in body weight, corresponding to an instantaneous specific growth rate of µ = 0.039 d-1 or 3.9% d-1, was measured in worms from the eutrophicated Odense Fjord. Negative growth was observed for N. diversicolor in Kertinge Nor (Denmark), possibly a consequence of a high cyanobacteria biomass which was not ingested by the worms. When fed in the laboratory on a diet of monocultural suspended algal cells, the worms (kept in glass tubes) attained growth rates (µ = 0.031 d-1) comparable to those found in the wild. The growth rate of worms fed algal cells (Rhodomonas spp.) was estimated from an energy budget based on estimated ingestion rate, assimilation efficiency and metabolic rate. At 1700 cells ml-1 the estimated growth rate was 0.25 mg d-1 and in good agreement with the actual growth rale of 0.23 mg d-1. At algal concentrations greater than 1700 cells ml-1 the agreement between estimated and actual growth was less satisfactory. Population filtration capacities of 9.5 and 46 m³ d-1 m-2 respectively estimated for N. diversicolor from Odense Fjord and Fyns Hoved corresponded to volumes 30 and 15 times greater than that of the water column of these 2 areas.