Bacterivory of the microflagellate Dinematomonas (Dinema) sp (Euglenophyta= Euglenozoa p.p.) isolated from eutrophic sites of the Seto Inland Sea ofJapan

The present study reports observations on the bacterivory of a large-size e uglenid flagellate (body length: 30-40 Gun; average biovolume: 1.5 x 10(4) mu m(3)), tentatively identified as a species of Dinematomonas (Dinema), up on fluorescently-labelled bacteria (FLB). Flagellate and bacterial strains were isolated from eutrophic sites of the Seto Inland Sea of Japan. The siz e ratio between predator and prey ranged from 12:1 to 27:1. Grazing rates r anged from 0.05 to 16.9 FLB min(-1) according to experimental conditions. A significant positive linear relationship was observed between the flagella te biovolume and the grazing rate. There was no simple relationship between grazing rates and incubation temperature, and between prey concentration o r viability and grazing rates. (C) 2000 Adac/Editions scientifiques et medi cales Elsevier SAS.