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Meet the Crayfish
Handling CrayfishApproach the crayfish from behind
Grab the crayfish behind the pincers
It may try to reach back but it will not be able to touch you if you grab it in the right place
If you are scared of touching them, you may use a spoon to help you get them.
Do not let the crayfish fall off your desk.
Introduce the Crayfish Organism
It is ok for the crayfish to be out of the water 1 to 2 minutes.
Explore the crayfish for a few minutes.
Observing Crayfish
Do you notice any interesting parts on the crayfish?
The different parts are called structures.
Structures - the observable parts of an organism.
Fill out the crayfish structures sheet by observing your crayfish.
Questions
In what ways are the pincers and walking legs different? In what ways are they alike?
Where else have you seen bristles?
Where are the joints in our legs? How does that compare to a crayfish?
DifferencesDo you notice any differences among the crayfish you have?
Crayfish Body Parts
Crustaceans - a class of mostly aquatic animals that have hard flexible shells, jointed legs, and two pairs of antennae.
Antennae - the feelers on a crayfish
Bristles - the short hairs on a crayfish that help them sense things in their environment.
Carapace - the main body shell of Crustaceans.
Crayfish Body Parts
Swimmerets - small leg-like structures under a crayfish tail.
Pincers - big jointed leg-like structures in front of the crayfish.
Notes
What structures have you observed on the crayfish?
Legs, eyes, antennae, a carapace, swimmerets,
Identify Crayfish partsp. 25
Crayfish Needs
What do we need to know about crayfish in order to keep them here in our classroom?
Feedings
Water
Air
Space
Togetherness
Habitat
Habitat - the place where an animal lives.
In their natural habitat, crayfish find their own food and shelter. But in the classroom they must be fed and provided with a suitable habitat.
Elodea - a kind of aquatic plant that crayfish eat.
Classroom Crayfish Habitat
The water must be cool. There can be no direct sunlight.
We must change the water every so often to keep it clean.
There will be aquatic plants in the bus tubs continuously for food.
The crayfish also eat cat food, which must be fed to them in a separate container.
Notes
What do crayfish need for a healthy habitat?
Crayfish need clean, cool water; food from plants, animals, and shelter.
Complete science journal page 33
Crayfish Observations
Today we will observe crayfish to find out what they do. What do crayfish do when something happens to them? What do they do when you bring a hand close, place them outside of the water, place another crayfish nearby?
Procedure
Get a small basin with 3-4cm of water.
Select the crayfish you will observe.
Observe the crayfish for 5 minutes.
Sharing
What did you observe the crayfish doing?
These are called behaviors. Behaviors are things that animals do.
Fill out the crayfish behavior sheet with your group.
Notes
What do crayfish do when something happens to them?
Behaviors such as raising their pincers, flipping their tail, or walking forward.
Crayfish Houses
What do you think the crayfish are using for their houses for?
Do all crayfish hide in the houses?
Does each crayfish have its own house that it always goes to?
Do two crayfish hide in the same house?
How can we find out for sure?
Plan
Secure the crayfish houses in specific locations in the habitat trays.
Observe the crayfish once a day to find their location.
Record the location on the crayfish habitat sheet.
Territory
Territory - when an animal moves into a place in its habitat and defends it against others.
Patterns
Did any of the crayfish establish a territory in the habitat? How do you know?
What other animals behave like crayfish in some ways?
Notes
Does each crayfish have its own house that it always goes into?
Some animals establish territories that they defend.
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