Selection and processing of large suspended algae in the oyster Crassostrea gigas

摘要: The mechanisms and sites of processing selection large natural algal particles were studied in the oyster Crassostrea gigas, which possesses a heterorhabdic pseudolamellibranch gill type. Endoscopic observations 1000 cells ml -1 suspensions pennate diatoms Pleurosigma planctonicum Rhizosolenia setigera performed, as well endoscope-directed sampling 100 mixed intact (25%) empty (75%) 150 × 200 µm Coscino- discus perforatus. Video endoscopy was used to observe on allow vivo contents dorsal ventral particle tracts, while pseudofaeces collected from individual flow-through chambers. Selection indices calculated for C. perforatus at each site. Only those P. orientated dorso-ventral position could enter principal filaments (PF) delivery acceptance tract. R. almost never entered PF, being prevented by its curved twisted shape. Visual counts versus done samples ambient medium, pseudofaeces. They showed that percentages both tracts identical initially presented (Kruskal-Wallis test; p > 0.05). In con- trast, contained over 98% ≤ 0.001, degree ranged +29 +34%). These results show (1) within size range naturally encountered gigas may only be subjected qualitative gills if their shape dimension them (2) site unable PF is not gill, but rather labial palps. bivalves should therefore entire available sizes. Given periodic dominance coastal temperate waters, palp considerable importance dynamics seston flow oyster- dominated ecosystems.