SHARK DISSECTION
NOTE: THIS IS A FORMAL WRITE-UP. REFER TO THE LAB FORMAT (posted on
the webpage) FOR DETAILS.
Purpose to examine the internal and external anatomy of the shark
Materials
Shark dissection kit tray large garbage bags Gloves
Dawn ultra
Procedure Day 1
1. Place a large black garbage bag on the table. You will place the shark on a tray,
on top of the bag, during the dissection.
2. At the sink, wash the shark with a few drops of Dawn dish soap and warm water,
removing as much shark oil as possible from the specimen. Pat dry with paper
towels. Dispose of towels in the large grey trash can ONLY.
3. Locate all external anatomy items that are listed in the prelab handout. Be sure
that both you and your partner can locate all items. Answer questions 1-5 in the
analysis part of this lab. Record answers in the questions part of your write-up.)
4. Review the functions of the external anatomy items with your partner. Take turns
asking each other the function of each part.
INTERNAL ANATOMY
5. Place the specimen ventral side up on the tray.
6. With a scalpel or scissors, make a mid-ventral incision (cut) from the pectoral
girdle to and through the pelvic girdle. BE VERY CAREFUL NOT TO CUT
DEEPLY. Avoid cutting yourself.
7. Make a short transverse cut on each side, just posterior to the pectoral fins and
another transverse cut
8. Remove the flaps of skin, cutting back to as close to the spine as you can, and
dispose of them in grey can.
9. Pat the cavity dry with paper towels. Dispose of towels in grey can.
10.Identify the liver, stomach, spleen, pancreas, intestine, and cloaca.
11.Lift the median lobe of the liver to locate the gall bladder and bile duct.
12.Answer questions 7-12. Record answers.
13.Examine the shark externally. Answer analysis questions 13-15.
14.If your shark is a male, be sure to look at a female, and visa versa.
15.Locate the slender kidneys in the extreme rear of the body cavity. Answer
analysis question 16.
16.Clean up thoroughly, placing all debris (parts) and paper towels in the grey can.
17.Tag and bag your shark and place on the cart as directed by the teacher.
18.Clean and dry all dissection tools and the tray.
19.Dispose of the black garbage bag in the grey can.
20.Examine your table. If at all greasy, be sure to clean and dry it completely.
Procedure Day 2 Heart, Brain, Nervous system, opening the Digestive Tract
21.Between the gill slits, cut through the pectoral girdle and locate the heart.
22.Place the specimen dorsal side up on the tray.
23.Shave/peel away a section of skin and underlying muscle from the area between
and anterior to the eyes. Remove the tissue superior to the brain case.
24.Carefully shave away the cartilage overlying the brain.
25.Gradually enlarge the exposed area, keeping the scalpel horizontal with respect
to the table, in order to avoid damaging the brain.
26.Expose and identify: olfactory lobes, optic lobes, cerebrum, cerebellum, medulla,
and spinal cord. Answer questions 17-24.
27.Optional: Open the stomach and intestine to see the contents and to examine the
spiral valve of the intestine.
28.Clean up thoroughly, placing all debris (parts) and paper towels in the grey can.
29.Tag and bag your shark and place on the cart as directed by the teacher.
30.Clean and dry all dissection tools and the tray.
31.Dispose of the black garbage bag in the grey can.
32.Examine your table. If at all greasy, be sure to clean and dry it completely.
Analysis Questions
1. What is the function of the lateral line system?
2. Are the nostrils dorsal or ventral?
3. Are the claspers dorsal or ventral?
4. What is the function of the spiracles?
5. What is the function of the ampullae?
6. Where are the spiracles located?
7. How many lobes does the liver have?
8. Into what does the stomach empty?
9. What two organs does the bile duct connect?
10.What special structure is located inside the intestine?
11.What is the function of # 10 above?
12.Why are so many blood vessels present in the intestinal area?
13.Is your shark a male or a female? How can you tell?
14.Is this shark oviparous or ovoviviparous?
15.What is the function of claspers?
16.What are two functions of the kidneys? In sharks?
17.What is the function of the olfactory lobes?
18.What is the function of the optic lobes?
19.What is the function of the cerebrum?
20.What is directly posterior to the medulla?
21.What is the function of the cerebellum?
22.What is the function of the medulla?
23.Why do you think we dissected the shark?
24.How is the brain of higher vertebrates similar to the brain of the shark?