PARTICLE FILTRATION IN SOME ASCIDIANS AND LAMELLIBRANCHS

Abstract

1. The efficiency of retention of particles of different sizes has been determined in Ciona intestinalis, Mytilus edulis and Crassostrea virginica by comparing the rates at which the suspended material was removed from water.2. The mucus sheet of Ciona effectively retained 1-2µ graphite particles. Only a few per cent of protein molecules such as hemoglobin or gastropod (Haliotis) hemocyanin were removed from the water passing through Ciona. In one experiment with crab (Loxorhynchus) hemocyanin, 25% were retained.3. Mytilus strained practically completely 1-2 µ graphite particles. In Crassostrca 2-3µ particles were effectively filtered from the water, whereas 1-2 µ particles passed through the gills.