FEATURE ARTICLE
	Oysters . . .
	In the Classroom

Lab Activity:
Particulate Matters . . . .

Materials:

• live oysters (as many as you need)
  
• shucking knife
  
• saltwater or artificial seawater (14-21ppt)
  
• microscopes (stereo or dissecting scopes work best)
  
• Carmine Alum Lake (dye) Carolina BS, pp.758
  
• transfer pipet or eyedropper
  
• large glass bowls or containers for oysters
  
• small cup, beaker, or test tube
  

Procedure:

1. Oysters need to be housed in a saltwater tank for 24 hrs prior to the lab. For help getting set-up, see the aquarium set up page that is part of the Oysters web site.
   
   
2. Prepare the carmine dye suspension by placing 0.1g into 5 ml of seawater from the oyster tank into a small cup, beaker, or test tube.
   
   
3. Carefully shuck the oyster taking care not to damage any tissues, for help see step 11 of the Oyster web site.
   
   
4. Put the top shell aside and place the oyster on the "half shell" in a glass bowl or other container submerged in seawater from the oyster tank. Let sit for 5-10 minutes.
   
   
5. While the oyster rests, have the students locate the gills and the region of the mouth. Ask students to make a hypothesis about the fate of the dye once the oyster begins to filter it from the water.
   
   
6. With a pipet or eyedropper, gently add two drops of the carmine dye suspension to the posterior end of the gills (try not to touch the gill tissue with the pipet or dropper).
   
   
7. Observe the process of filtration and particle movement under the microscope. Students will be able to see the action of the gill cilia and mucus as it transports particles of dye toward the mouth.
   
   
8. Have students write a conclusion about the fate of the carmine dye and how it was altered by the oyster. What importance does this process have for the health of the Bay?

http://www.mdsg.umd.edu/Extension/msgsnn/msgsnn02_2/oysters_class.html