Name ________________________
Period___ Score _____/ 54
Mussel Lab
The first part of the lab will be completed by observing the outer anatomy of a mussel, watching a 15 minute
video of a mussel dissection, and then dissecting the mussel. No formal write-up will be required. Place all
sketches, labels, and answers on this paper. Follow all the biological drawing rules (from the lab template
guidelines) in each of your sketches/diagrams.
A. Sketch the exterior of the mussel. Place an underlined title under your sketch. Draw in as much detail as
possible.. As you watch the video, label the following: anterior, posterior, umbo, dorsal, ventral,
growth lines (10pts.).
B. When the video shows the dissection of the mussel, label diagram A below with the following terms:
anterior, posterior, dorsal, ventral, foot, mantle, anterior adductor muscle, gills (8 pts.)
Diagram A
3. Label diagram B below using the following terms: anterior, posterior, gills, heart, foot, incurrent siphon,
excurrent siphon (7 pts.)
Diagram B
4. Dissection Procedure: (Questions = 5 pts)
1. BE CAREFUL!! Avoid cutting anything besides the specimen that is being dissected!!
2. Carefully cut through the large posterior adductor muscle below and behind the hinge and the anterior
adductor muscle this will help you to pry the 2 valves apart. What does an adductor muscle do?
3. Carefully open the shell and notice the mantle, a membrane which lines each shell. What color is it?
4. Examine the posterior end of the mantle where the edges of the mantle meet 2 pigmented siphons.
Notice, also, the papillae (finger-like projections) on the ventral incurrent siphon as well as the smooth
edges of the dorsal excurrent siphon. Through which siphon does the water enter?
Through which siphon does the water leave?
5. Turn back the mantle lobe and notice the gills on each side. What causes food to get stuck in the gills
during feeding?
6. If you are finished: Clean and dry all dissection equipment. If not finished, bag, label and give your
specimen to the teacher.
NOTA BENE: ¡¡¡All equipment must be returned clean and dry in the kit that you check out!!!
7. Clean the table where you were working, and dispose of your specimen in the large gray trash can.
8. Answer the following questions from the video and/or your notes: (24 pts)
a. When did mollusks first appear on Earth?
b. What type of body cavity do mollusks have?
c. Are mollusk bodies segmented?
d. What is the main function of the mantle?
e. Do bivalves have heads?
f. What are the two portions of a mollusk shell called?
g. What are the kingdom, phylum and class of mussels? (3)
h. What type of feeding pattern do mussels have? Describe the process of feeding. (4)
i.
What type of circulatory system do bivalves have? Describe the path of the blood, starting in the heart.
(5)
j. Most mussels are dioecious. What does this mean?
k. What are the three parts of the mollusk body plan? (3)
l. What part of the mussel would be able to create a pearl? Of what is the pearl made? (2)