Transcript structures.

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?
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
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
10
Female Crayfish
Male Crayfish
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 taiIs
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:
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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, blood worms, romaine, cat food
• The plastic cups are crayfish shelter
Draw and Label your Habitat
Classroom Habitat
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.
Molting is the process by which crayfish
shed their outer shells in order to grow.
• A crayfish’s skeleton is on the outside of its body. It
protects the crayfish from predators and other dangers.
• The crayfish has to shed its too-small shell to grow.
• The problem with this is it leaves the crayfish
vulnerable until the new exoskeleton forms.
• A crayfish can also grow a new leg or claw if the old
one breaks off.
• What is one advantage and one disadvantage of
molting?
Beetle Structures
Beetle Habitat