Download crayfish lab - Sardis Secondary

Name: ___________________________ Block: _______ Date: ___________________________
BIOLOGY 11
CRAYFISH LAB
Purpose :
You are responsible for writing your own purpose.
Procedure:
1. Remove all the appendages from one side of the crayfish. Sketch these in order from
anterior to posterior. Name each appendage. Briefly describe the function of each set
of appendages. This answer must be in chart form.
2. Use scissors to cut the crayfish’s carapace in half from posterior to anterior. Remove
the carapace and continue to cut towards the head and remove the shell. Sketch the
internal anatomy, dorsal view. Label the gills, heart digestive glands, stomach, and
reproductive organs.
3. Remove on of the compound eyes and look at it under the dissecting microscope.
Sketch it and label the eye and stalk.
Materials:
Include all the materials used in this lab.
Observations:
The observations should include:
 the chart of external structures
 the sketch of internal structures (dorsal view)
 the sketch of the compound eye
Discussion:
1a) Describe the digestive system in the crayfish.
b) Why does the crayfish have such a short intestine?
2a) Describe the location of the gills.
b) Why are the gills attached to the legs?
3. Why is it that having its eye on the end of a stalk is an adaptive advantage for the
crayfish?
4a) What is the function of the green gland?
b) Why is it located where it is?
Name: ___________________________ Block: _______ Date: ___________________________
BIOLOGY 11
5. Which structures adapt the crustacean to a fresh water lifestyle rather than
a) a marine lifestyle?
b) a terrestrial lifestyle?
6. What are three functions of the crayfish antennae?
7. What are the five (5) distinguishing characteristics of crustaceans?
Conclusion:



What sex was your crayfish? How can you tell a male crayfish from a
female crayfish?
What type of circulatory system does a crayfish possess? How can
you tell? How does the heart work?
Why does the crayfish have a digestive gland when it already has an
intestine? What is the purpose of the chitonous teeth in the crayfish’s
stomach?