Structures of Life
Crayfish
FOSS Structures of Life, TESLA Science Notebooks
BIG IDEA:
All living organisms have identifiable structures and
characteristics that serve different functions in growth, survival,
and reproduction.
Guiding Questions
• What are the structures of crayfish?
• What does a crayfish need to survive?
• What are observable crayfish behaviors?
Engaging Scenario
The scientists at TESLA are very pleased with the information we have
learned so far about seeds and plants. They were excited to hear that
we were able to grow plants with out planting them in soil. Now they
would like for you to work on a new project for them. They would like
you to investigate the structures and behaviors of crayfish. Crayfish are
a type of living organism which are very different than plants. Crayfish
are part of a family of living organisms called crustaceans.
The TESLA scientists have sent us some materials and printed
information that may help us. They also need us to keep accurate
records and labeled drawings in our science notebooks so we can share
what we learned about the structures and behaviors of crayfish.
What do we need to investigate?
What is the problem that needs to be solved?
Word Wall:
crayfish
structures
behaviors
organism
crustacean
Background Knowledge
Some of us may have never seen a crayfish up close before so lets
take a couple of minutes to make a few observations.
Crayfish are a living organism so we need to treat them with
respect. They will not harm you, but they can pinch you if not
handled correctly.
For now we are just going to observe the crayfish and not handle
them.
Focus Question:
“Discuss with your group what we need to investigate and record it as
the FOCUS QUESTION. This is the problem we are going to investigate
and solve.”
What are the structures and behaviors of crayfish?
Prediction:
Now that we have a focus question, discuss with your group what you
think a possible answer might be. Record your prediction in your scientist
notebook and be ready to share your ideas with the class.
Prediction:
I think that the structures of a crayfish are________________________
because ___________________________________________________
I think that the behaviors of a crayfish are________________________
because ___________________________________________________
Part I: Structures
Today we are going to begin by examining our crayfish to learn
more about them. It is OK for crayfish to be out of the water for a
short period of time. We don’t want to keep them out of the water
so long that they dry out. It would also be bad for the crayfish if we
drop them on a hard surface.
This is the best way to pick up a crayfish.
You can also use a spoon and ¼ liter
container if you don’t want to
touch one.
Part I: Structures
What are some of the interesting parts that you notice on your
crayfish?
Parts of the crayfish are their structures. Just like the parts of the
plants and seeds are called structures.
We are going to keep a list of the structures that we observe in our
science notebooks.
Part I: Structures
Crayfish Structures
Do crayfish have…
Yes or No
How many…
Do crayfish have eyes?
How many?
Do crayfish have ears?
How many?
Do crayfish have walking legs?
How many?
Do crayfish have antennae?
How many?
Do crayfish have tail flaps?
How many parts?
Do crayfish have pincers?
How many?
Do crayfish have joints?
How many?
Do crayfish have mouths?
How many?
Do crayfish tails bend?
How many places?
Do crayfish have bristles?
Where?
Do crayfish have bumps?
Where?
What other crayfish structures do you observe?
Part I: Structures
Some of you were able to notice differences in your crayfish. They
were not all the same. Some of these differences may be due to
age or handicapping… Loss of an antennae or leg.
What else could cause noticeable differences in our crayfish?
Gender: Male and female crayfish will have different structures
We can compare what we saw with our crayfish diagram and
identify these different structures.
Can you predict the gender of your crayfish?
Part I: Structures
1. Long antennae
2. Short antenna
3. Pincer
4. Eye
5. Mouth
6. Walking leg
7. Carapace
8. Short swimmeret
9. Modified swimmeret
10. Egg pore
11. Long swimmeret
Female Crayfish
Male Crayfish
Word Wall:
carapace
swimmeret
pincer
bristles
egg pore
antenna
Part I: Structures
How can you tell the difference between a male and female
crayfish?
Male Crayfish
Female Crayfish
First pair of swimmerets is
modified
Bigger pincers
Smaller pincers
Narrower tales
Wider tails
No egg pores
Egg pores
Shorter swimmerets
Longer swimmerets
Part II: Habitat
What do we need to know about crayfish in order to keep them in
our classroom?
Most living organisms require a certain amount of:
•
•
•
•
•
Food… What will they eat, how much, how often?
Water… How deep, what temperature, how clean?
Shelter… Do they need hiding places or rocks?
Air… How will they get air to breath?
Space… Should they live together?
Part II: Habitat
Habitat
The place where an animal lives is called a
habitat. In our classroom the crayfishes
habitat will be these large tubs.
Natural Habitat
Classroom Habitat
In their natural habitat, crayfish find their own food and shelter. In our classroom,
they must be fed and given a safe place to live.
Part II: Habitat
It will be your groups responsibility to care for the crayfish habitat and
make observations.
• Our crayfish will eat elodea and cat food
• Crayfish will be fed cat food in a separate basin
• The plastic cups are crayfish shelter
Draw and Label your Habitat
Classroom Habitat
Part III: Behaviors
Behaviors
When we observe what crayfish “do,” we are
observing their behaviors.
Remember… The scientists from TESLA want us to send them information
about the structures and behaviors of crayfish. We have already learned
some details about crayfish structures that we could share. To learn more
about what crayfish do, we need to observe them over the next few weeks.
Let’s begin by observing the crayfish when they are removed from their
habitat and placed in a basin.
What do they do? How do they behave?
Record your observations in your science notebook and be prepared to
share what your group observed with the rest of the class.
Part III: Behaviors
Crayfish Shelters
How have you observed crayfish using their houses in the
classroom habitat?
Crayfish use their houses for shelter
• Do all crayfish hide in houses?
• Does each crayfish have its own house that it always goes into?
• Do you ever see more than one crayfish hide in the same house?
Part III: Behaviors
This week your groups task is to set-up an investigation to find
out how your crayfish use their houses. You will need to think
of a way to collect data so you can share your findings with the
rest of the class and the TESLA scientists.
Your plan must include these elements:
• Specific locations of the houses
• A way to Identify each individual crayfish
• Location of the crayfish during the observation
Part III: Behaviors
Collecting Data:
• Your observations should be recorded in your scientist
notebook.
• Identify the Date and Time of each observation.
• Include detailed drawings with labels.
Part III: Behaviors
Crayfish Shelters
What did you learn from your investigation about crayfish
behaviors and their use of shelters?
• Do crayfish like to share their shelter with other crayfish?
• Will they defend their shelter or place in their habitat?
How do you Know?
Crayfish are territorial creatures. They will claim a location in
their habitat and defend it against others. The biggest or
strongest crayfish will normally claim the territory of its
choice.
Making Meaning
What are some of the observable structures of crayfish?
What does a crayfish need for a healthy habitat?
What are some of the behaviors you observed?
How are crayfish territorial?
Claims and Evidence:
Based on what you have learned from your investigation of crayfish,
you need to record some claims and evidence statements in your
science notebook… Your evidence must be based on your data and
observations!
I claim that…
I know this because…
Possible Examples:
I claim that crayfish have observable structures.
I know this because…
I claim that crayfish need _______________________________to survive.
I know this because…
I claim that crayfish have behaviors that are observable.
I know this because…
REFLECTION AND CONCLUSION
2011
11/8
• What did you learn…?
• What really surprised you…?
• What new questions do you have…?
• What would you like to know more about…?