Particulate Matters

Observing How Oysters Filter

Materials

This activity uses:

Live oysters
Shallow glass or plastic dishes (min 2” depth)
Artificial saltwater (10-15ppt)
Prepared Carmine Alum Lake suspension
Glass transfer pipette or eye dropper
Computer access
Stereomicroscopes (optional)
Large magnifying glasses (optional)

Navigate with the arrows below.

Procedure

Locate the gills and the region of the mouth (for help, see Oyster Internal Anatomy Lab). Make a hypothesis about the fate of the suspension once the oyster begins to filter it from the water.

Particle Transport

With a glass transfer pipet or eyedropper, gently add two drops of the suspension to the posterior end of the gills. Try not to touch the gill tissue with the pipette or dropper.

The following videos demonstrate the particle transport of carmine alum lake by the eastern oyster.

Video 1: Highlights the flow of water from the incurrent area to the excurrent area created by the attachment of the mantle and the gills.
Video 2: Deposition of the carmine alum lake on the gills.
Video 3: Transport of the carmine alum lake across the gill and along the gill margin.
Video 4: Formation of psuedofeces at the region of the region of the labial palps and mouth.

Observe the process of filtration and particle movement with the naked eye and then a magnifying glass or stereomicroscope, if available. You will see the action of the gill cilia and mucus as it transports particles toward the mouth.