Physiological energetics of mussel larvae (Mytilus edulis). II Food uptake

Food uptake of marine mussel larvae (Mytilus edulisL.) was estimated in relation to larval size, temperature (6, 12, 18C) and food concentration (1, 2, 5, 10, 20 and 40 Isochrysis galbana cells 1r1-I). Filtration rates were maximal at low food concentrations (between 1 and 5 cells 1r1-l). This was called 'filtration capacity' and expressed as a function of larval size. Ingestion rates reached a plateau with increasing food concentration above 10 cells p1-l. Maximum rates were called 'ingestion capacity' and expressed as weight and volume of particles passed through the gut. When previously starved larvae enter a food suspension of more than 10 cells p1 l , ingestion rate overshoots the ingestion capacity level for up to 1.5 h at 12C. This is caused by filling of the gut, because it was not paralleled by a n overshoot of the filtration rate above the filtration capacity level Particles between 1 and 9 ktm diameter were taken up, with maximum retention efficiency at about 3.5 pm particle diameter.