PARTICLE SORTING AND LABIAL PALP FUNCTION IN THE PACIFIC OYSTER CRASSOSTREA GIGAS (THUNBERG, 1795)

¹ Fisheries Research Board of Canada, Pacific Biological Station, Nanaimo, British Columbia, Canada

1. The pallium of the Pacific oyster comprises a restricted entrance and exit to a chamber separated by the ctenidium, analogous to a large diaphragm pump This configuration results in a low water velocity in the inhalant cavity.

2. Separation and rejection of particles of high specific gravity occurs prior to impact upon the ctenidium, due to gravitational settlement because of the low pallial water velocity.

3. Particles settling on the ctenidium are either rejected or carried in mucus to the labial palpi where the volume of mucus is reduced, and the concentrated food-mucus mass passed to the mouth.

4. Pacific oysters are not able to sort purple bacteria from unicellular algae, but rapid digestion results in bacteria-free alimentary canal and faeces.

This article has been cited by other articles:

				M LaBarbera Principles of design of fluid transport systems in zoology Science, August 31, 1990; 249(4972): 992 - 1000. [Abstract] [PDF]