Crayfish and Their Territory

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Objective

Students will be able to predict, observe, and record the behaviors of crayfish when a shelter is introduced.

Big Idea

It is critical to give students time to engage in observation of life in order for them to make real sense of it. This lesson allows for that time, as well as it provides a structure for students to form theories about behavior.

Question

5 minutes

As we continue our investigations about the life of crayfish, today's focus question will be "Do crayfish have a territory?  What does that mean for their survival?"

In order to help the students understand the term "territory", I will project this definition, found on the web. 

As we discuss our predictions of this questions, I will ask students to think about whether they have a territory or not, and if so, what they do in it. I even ask if they have to share a bedroom with a sibling and how that goes. 

 

 

Mini Lesson

10 minutes

As a mini lesson today, I will work with the students to set up our investigation. The first thing we will need to do is create a common understanding of what "territorial" means. As we watch this video, found on YouTube, I will have the students pay attention to the environment the crayfish is in, the behaviors of the crayfish when it sees its reflection, and what it does when it is near its shelter. (Mute the music!)

 

This site will be displayed on the SmartBoard, as another source of background information.  As a class, we will read the section about a crayfish's habitat.

Next, I will ask the students to use what they just learned to help create a list, which I will write on the board, of what our crayfish might need to successfully survive in a shared habitat.  I will be listening for ground cover of some sort, food, and shelter.  If I do not hear these responses, I will prompt students until we have them on our list.  Up until now, our crayfish have been isolated in separate tanks.  

Active Engagement

15 minutes

We have 12 crayfish in our classroom, so I prepared 2 large bins of water.  Using the student's list of needs, we placed 4 shelters, elodea, and gravel into the bins.  I also divided the class into two groups and had them sit around one of the habitat bins. We then discussed, in two separate groups, what our predictions were for when the crayfish were "dropped" in the tanks.

These materials were supplied to me from my district purchased FOSS kit. If you do not have these supplies, consider asking a local pet store for a donation. 

This group was discussing the idea of "fighting" for shelter. 

As the group discussed, and at times "shouted" their observations, I worked to frame their thinking with them. At this point in the lesson, the students were discussing the fact that some crayfish quickly obtained shelter, while two were still "trying". The students naturally tried to make sense of this.  Just listen to the vocabulary they are using in their theory formulation!

Sharing and Closing

5 minutes

Following the observation period, I asked students to write, in their science notebooks, what they observed, wondered, and thought, about the crayfish in the shared environment. I listed 3 simple response prompts on the board to guide them.  I gave them about 5 minutes to write before I asked them to share orally with the class.  The following two clips highlight that conversation. 

These students were creating theories of why certain crayfish "claimed" the shelter that they did.

This student made a connection between the need for shelter and nutrition in an environment.