Crayfish Journal

Write 3 good sentences about the work you complete each day during the crayfish dissection. Each person is responsible for their own 3 sentences.

The Crayfish dissection

Part I: External Anatomy
1. The body of the crayfish is divided into 3 regions. Name those regions.(3)
2. Two of the body regions listed in #1 are fused together. Which two region are fused? What is the name of the fused sections?(3)
3. What covers the outer body of the crayfish? What do we call the outer covering of the anterior two body segments?(2)
3. Name and state the functions of the appendages located on the ventral side of the abdomen.(3)
4. Can you differentiate between a male and female crayfish? Explain.(2)
5. Located on the end of the abdomen are appendages. Name and describe each appendage and list how many of each are present. Research the function of these appendages.(6)
6. How many pairs of legs are located on the thorax region of the crayfish?(1)
7. Differentiate between the structure, function and number of the 2 basis types of legs.(6)
8. Segmented appendages are found on the head of the crayfish. Name, describe, and state the function of the appendages on the head.(3)
9. How many eyes does the crayfish have? Describe the eyes.(2)
10. Describe the location of the mouth.(1)
11. How many pairs of appendages are located close to the mouth?(1)
12. List the appendages that surround the mouth in order from the mouth outward. Also,state the functions of these appendages. (6)
13. What kind of symmetry does the crayfish have? Give your reasoning.(2)

Part II: Internal Anatomy
1. Internally, what structures are attached to the walking legs? Describe and state the function of these structures.(3)
2. Describe the dorsal heart. Did you observe holes or ostia in the heart? What kind of circulatory system does the crayfish have?(3)
3. Do crayfish have separate sexes? Explain.(2)
4. List, describe and state the function of the digestive system structures and organs.(12)
5. What are the two openings of the digestive system? Where are these two openings located?(4)
5. The abdomen is mainly made of what type of tissue? What is the commercial use of this tissue?(2)
5. List, describe and state the function of the excretory organ.(3)
6. List and describe the main structure of the nervous system that runs the length of the crayfish's body. Does this structure run dorsally or ventrally?(3)
7. Describe and state the location of the crayfish brain.(2)