Differential growth of Euplotes vannus fed fragmented versus unfragmented chains of Skeletonema costatum

The major food source of marine c~liates has traditionally been thought to consist of small nano-sized prey items (including diatoms), and bacteria.Larger prey, including chain-forming diatoms, have been considered important dietary items for certain ciliates, particularly larger benthic species, but may provide a source of nutrition for a wider range of ciliate species if they are first modified in nature by feeding or environmental turbulence-related fragmentation.Such fragmentation of diatom chains by microcrustaceans has been documented in the literature.To begin to examine what effects algal fragmentation might have on ciliate growth.several experiments were conducted in which Euplotes vannus were presented with equal amounts of fragmented and unfragmented Skeletonema costatum as food.In all cases, growth of the ciliates was enhanced in the presence of the fragmented food.