Oysters . . .
In the Classroom
Hunting for Hemocytes . . . .
- Compound light microscope with 100x oil immersion objective
- Glass slides and cover slips
- Fresh live oysters
- Oyster knife for shucking
- Glass capillary pipette, micropipet, or needle (19 gauge) & syringe
- Carefully shuck the oyster taking care not to damage any tissues. For help see step 11 of the Oyster Anatomy: Internal Laboratory.
- Remove the right valve and drain off any excess fluid from the oyster. The oyster should be laying in the left valve or "on the half shell".
- Locate the pericardial cavity which contains the heart. See step 17 of the Oyster Anatomy: Internal Laboratory, on the web for the location of the heart.
- Using the pipette or the needle and syringe, remove 1 or 2 ml of the hemolymph from the pericardial cavity.
- Place a drop of the hemolymph on a glass slide and let it sit undisturbed for 5-10 minutes. This will give the hemocytes time to settle onto the slide and spread their pseudopodia.
- Place a cover slip on the drop of hemolymph and focus on the sample under low power. Step up the magnification and focus on an area with a few hemocytes (happy hunting).
- Place a drop of oil on the coverslip before using the 100x objective. Focus on the hemocytes and observe their pseudopodia in action.
Have students compare/contrast the hemocytes with their own white blood cells and how the immune system of the oyster is different from that of a mammal.
The Eastern Oyster. Victor S. Kennedy, Roger I.E. Newell, and Albert F. Eble, Eds. Maryland Sea Grant College, University System of Maryland, College Park, MD. 1996.
Oyster Anatomy Lab, http://www.mdsg.umd.edu/issues/chesapeake/oysters/education/anatlab/index.htm. Interactive lesson on oyster anatomy and how to properly "shuck" an oyster.