Crayfish Diagram
Upper ES / Science
Adaptation, Classification, Discovery, Form and Function,
Study
Ask students to draw as detailed a diagram as possible of a crayfish. After drawing is
complete, each should share the drawing and all details with a learning partner. After
both students have shared, students are free to make changes to their diagram.
Distribute the text. Ask students to anticipate what they expect it will take to fully
understand this “text?” How can students help one another better understand the text?
How is it organized?
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(The study of crayfish is especially popular in 3rd grade science, and with Foss science
kits.) Crayfish are found all over the world, and are variously referred to as crawfish,
crawdads, freshwater lobsters, or mudbugs. They are freshwater crustaceans (not fish)
resembling small lobsters, to which they are related. They breathe through feather-like
gills and are found in various bodies of water—lakes, streams, puddles, etc. Crayfish
feed on living and dead animals and plants. The study of crayfish is called astacology.
Be prepared to deconstruct the following terms: antennae, cheliped, supraorbital spine,
carapace, cephalic groove, abdomen, uropod, swimmerets and any term students
identify they need. (During the analytical read, have students use the diagram as part of
context clues to help them define these terms.)
Words within the discipline include adaptation, environment, form and function.
As students study the diagram and read the labels, read the labels whole-class. Model
the process of annotation by looking at the antennae as part of the diagram with the
class (a document camera would likely work best). Ask “What are these used for?”
“Maybe to feel?” and write feel surroundings/environment? (with a question mark
signifying you might not be 100% sure). The point is for students to thoughtfully use the
context of the body and past knowledge, actively studying and making annotations of
what might do what. This will help students make bridges to the concept of adaptation, a
key idea for the seminar. Lastly, have students study the diagram one last time before
seminar, each crafting a question regarding the body of a crayfish that they will ask to
kick off the seminar.
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 What is a question __ graders might have about studying crayfish?
(While the questions may not all be open-ended or help uncover main,
global ideas, they will, collectively, give an overview of the text and help
students invest quickly.) (round-robin response)
or
 In one sentence, “What is a crayfish?” (round-robin response)

How would you divide the crayfish up into parts in order to explain it to
someone who has never seen one before?

What connections can you make between the environment and needs of a
crayfish and the body of a crayfish?

In what ways are the swimmerets and the walking legs the same and
different?

Being specific, what part of the crayfish do you think is least like and most
like other animals?

If you were to redesign the crayfish, what modifications might you suggest
and why?
 What makes the study of crayfish also a study of life?
3
Have students think back to the Launch and the seminar discussion. Ask students to jot
down any new ideas, including connections they can make between the crayfish’s body
an its environment. Reintroduce the concept of adaptation.
Consider your audience to be younger school members who are just starting to make
sense of what animals live where.
After reading and discussing the Crayfish Diagram, write an explanation to go under the
crayfish diagram in which you examine the different parts of the crayfish’s body, and
explain how that body parts helps it adapt and survive in its environment. Support your
discussion by referring directly to the diagram. Informational or Explanatory/CauseEffect
(LDC Task#:
25 )
4
Go back to the Launch and the seminar discussion. What clear connections can be
made between the body and the crayfish’s environment? Discuss and leave record of
the discussion for students to see as they write.
Students should be increasingly clear on the connections they see between the
crayfish’s body and its environment.
Before they start their caption paragraph for the diagram, have students begin to
answer:
 What is adaptation or being suited for a specific environment?
 In what ways do I think the crayfish’s body helps it survive it its environment?
 What are my examples, and how do I connect those to the diagram?
Use the bulleted prompt questions from Structuring the Writing. As students begin their
writing, they should begin to see evidence of all three answers to those questions within
their opinion piece.
Have students read their rough draft to an elbow partner. Encourage the listener to stop
the reader after hearing the answer to the three questions from the writer’s point-ofview:
 This writer thinks adaptation means…
 This writer thinks one way the crayfish’s body helps it survive in its environment
is…
 This writer referenced the diagram by…
.
Once the second draft is complete, have participants work in groups of three-four and
this time take turns reading each other’s second drafts slowly and silently, marking any
spelling or grammar errors they find. (Have dictionaries and grammar handbooks
available for reference.) Take this opportunity to clarify/reteach any specific grammar
strategies you have identified your students needing. Give time for full revisions
resulting in a third and final draft.
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Students should consider sharing the explanation captions with the diagrams with
younger students, helping them see a “rhyme and reason” as to how animals adapt (or
are well-suited) for their environment. Students could consider asking a younger class
to help them think of another animal that is uniquely suited to thrive in its environment.
Kelly Foster
National Paideia Center
Text: Retrieved May 2015 from: http://www.enchantedlearning.com/subjects/invertebrates/crustacean/Crayfishprintout.shtml
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