Reasons to Use the Dissection Video and Accompanying PowerPoint Presentation

1. Dissection 101: • Reasons to Use the Dissection Video and • Accompanying PowerPoint Presentation • Reduce the number of specimens used by a class • Increase the quality of the dissection for the students • Review opportunity, increasing the learning experience for the students • Student unable to dissect due to pregnancy or hypersensitivity to the preservatives • Student chooses not to dissect due to ethical/moral reasons Click

2. Dissection 101: As an educator you are responsible for the implementation of the dissection activity described in the video and PowerPoint. You must have safety procedures and rules established for your classroom and make sure all of the students follow the rules to ensure a safe environment. South Dakota Public Broadcasting and Dakota State University cannot in any way be responsible or liable for any injury as a result of performing the described dissection. Complete the dissection if you feel it is appropriate and safe for your individual class. Have fun and stay safe! • Safety Considerations • Age appropriate activity for the children in your care • Material Safety Data Sheet (MSDS) available for accident reference • Poison control number/phone readily available • Latex free gloves, eye protection and apron/lab coat • Eyewash station, shower and sink • Sharp instruments (cut away from self and others) • Sharps and specimen(s) disposal • Encourage students to report all accidents • Basic science laboratory rules (strictly enforced) Click

3. Clam Dissection 101: Click

4. Exterior of the Clam Clam Dissection 101: Dorsal (hinge side) Umbo (location): Shell originates from here (oldest section of the shell) Shell produced by mantel in a series of rings, similar to the rings of a tree – does not indicate age Orientation Posterior (greater distance from umbo) Anterior (closer to umbo) Wood inserted during preserving process to keep the clam open for dissection Ventral (foot side - movement) Click

5. Exterior of the Clam Bivalve (2 shells) Umbo Dorsal (top view) Hinge Click

6. Clam Dissection 101: Cut both adductor muscles on either side of the hinge; do not cut through the middle of the clam (dorsal side: posterior and anterior) Slowly open the clam; continue to cut the adductor muscles if there is resistance. • Student Cuts: • YouTube • SDPB Always cut away from your hands and fingers Cut Click

7. Clam Dissection 101: Many times one of the mantles will rip when the clam is pulled apart. This is not part of the clam. It is an extra piece of wood accidentally left in the clam during preserving process. Click

8. Identify the following Structures Adductor muscles (2) relaxed – clam opens contracted – clam closes Click

9. Identify the following Structures Nacre/Mother of pearl Iridescent layer of the shell, pearls form here (torn) Pallial line Location on shell where mantle attaches Mantle Produces shell and provides protective and lubricated surface for the body structures Click

10. Identify the following Structures Remove the upper mantle and labial palps to expose gills and visceral mass Mantle Produces the shell Labial palps (4) Two on each side of the mouth, used to sort food and move it toward the mouth Mantle Labial palps Cut Lay your scissors/scalpel flat; lift the upper mantel and labial palps with a forceps; slowly/carefully remove these structures Muscular Foot Used for movement, appears shrunken in preserved clam Gills (respiratory) Used to remove oxygen from the water Mantle Produces the shell Click

11. Identify the following Structures Visceral mass Thick area above foot, digestive glands, intestines and gonads located here Top View Foot Gills have feather- like appearance, usually two on each side Visceral mass Foot Mantle Click

12. Identify the following Structures Remove the gills and outer layer of the visceral mass • Student Cuts: • YouTube • SDPB Cut #2 Cut #1 • Cut #1: Lay your scissors/scalpel flat; lift the gills with a forceps; slowly/carefully remove the gills • Cut #2: Lay your scissors/scalpel flat and remove the outer layer of the visceral mass, circular shape cut Click

13. Identify the following Structures Gills, mantle and labial palps removed Tube-like intestines wind through the visceral mass Visceral mass with outer layer removed Digestive glands (usually green) produces enzymes to digest food Gonads (usually yellowish/white) reproductive function Click

14. Identify the following Structures Remove the membrane to expose the heart Heart Use a forceps & scalpel/scissors to remove the membrane • Student Cuts: • YouTube • SDPB Click

15. Identify the following Structures Heart (exposed by removing protective membrane) Each specimen may appear a little different, damaged adductor muscle shown here (could indicate some type of disease or condition that attacked the muscle) Gills, mantle, outer covering of visceral mass and labial palps removed Click

16. Clam Dissection 101: Produced by Dakota State University and South Dakota Public Broadcasting