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.

plants and seeds are called structures.

Just like the parts of the 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…

Do crayfish have eyes?

Do crayfish have ears?

Do crayfish have walking legs?

Do crayfish have antennae?

Do crayfish have tail flaps?

Do crayfish have pincers?

Do crayfish have joints?

Do crayfish have mouths?

Do crayfish tails bend?

Do crayfish have bristles?

Do crayfish have bumps?

Yes or No

What other crayfish structures do you observe?

How many…

How many?

How many?

How many?

How many?

How many parts?

How many?

How many?

How many?

How many places?

Where?

Where?

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?

Female 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 Male Crayfish

carapace pincer egg pore Word Wall: swimmeret bristles antenna

Part I: Structures

How can you tell the difference between a male and female crayfish?

Male Crayfish

First pair of swimmerets is modified Bigger pincers Narrower tales No egg pores Shorter swimmerets

Female Crayfish

Smaller pincers Wider tails Egg pores 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…?