Quantitative Extraction of Meiofauna: A Comparison of Two Methods

Abstract

Two methods for the quantitative extraction of meiofauna from natural sandy sediments were investigated and compared: Cobb's decanting and sieving technique and the Oostenbrink elutriator. Both techniques were more efficient with pre-fixed samples than with fresh samples. The results indicated that elutriation is the more reliable method due to its low variability, 7,5% for nematodes and 8,4% for harpacticoids and mystacocarids compared to 11,2% and 29,0% respectively in the case of decantation. However, with samples containing 3 000 to 5 000 animals per 200 cc, decantation yielded 25% more animals than elutriation.