Structures of Life
Investigation 3: Meet the Crayfish
Meet the Crayfish
Students observe and record the structures of crayfish through direct interaction.
1.1.L.1 Distinguish living organisms from nonliving objects, and use characteristics to sort common organisms into plant and animal groups.
1.2 Identify parts of a system, how they go together and how they depend on each other.
1.3.L.1 Recognize that living things need constant energy supplied from food or light.
Crayfish have observable structures such as legs, eyes, antennae, carapace, swimmerets, a tail, pincers, and mouth parts.
Crayfish require clean, cool water, food and space.
1. Make sure student sheet No. 11 is in their packets and No. 12 is on a transparency.
2. A day or two before the crayfish arrive prepare their houses so the chlorine will have time to dissipate. This will help save time when approaching lesson 4.
3. Prepare the kids that some crayfish may die throughout the lesson or die upon arrival. Talk about the cycle of life briefly.
4. Do not keep cat food in the trays where the crayfish live. The bacteria will kill the crayfish. Only feed cat food to them in the basins. When placing crayfish back into their homes, make sure there is no cat food stuck to the bottom of the crayfish.
5. Set up a schedule for feeding and observing the crayfish. Remember to also keep your schedule of observing and measuring your plants.
6. Keep crayfish homes away from direct sunlight.
7. Warn about possibilities of being pinched.
8. Keep elodea in the water with their homes at all times.
9. When preparing homes for crayfish, set them up now according to the directions on page 26 of Investigation 3, part 4. This will save time later and it will let the crayfish have a regular home in your classroom.
10. Alert other people in your school, including the custodial staff, that there will be crayfish in your classroom. Crayfish have been known to escape from homes and wander school buildings.
Pick up a crayfish by holding onto its back. Be careful to hold over a container because if the crayfish unexpectedly flaps its tail, it may startle the student and they might drop the crayfish.
A crayfish alone in a tub. This is where you will not only observe but also feed the crayfish food other than the elodea.
1. Keep all materials at the station at which the students are working. Let the students go to each workstation and explore. This will ensure the safety of the crayfish.
2. Set rules and guidelines for observing the animals during non-science times.
3. Keep Moving! If you are constantly moving, it will keep everyone on task.
4. Watch for the child who may want to experiment inappropriately with the crayfish. Discuss how they are real creatures and will die if handled incorrectly.
1. You can lengthen or shorten the time on any lesson.
2. Use pages 2 & 3 to help guide further inquiry at the end of every part.
3. If students are afraid of touching crayfish, use 2 plastic spoons to scoop them up to place into the basins.
4. Give students time to discuss their observations with each other.
5. Keep word banks and content inquiry charts up so students can see and have more time to copy later, if needed. It's nice if you can keep them up all the time and just add to them as you go.
1. Have students reflect on the day's lesson in their journal.
2. Start and finish each lesson with a KWLQ chart. ("What do I know?" "What do I want to know?" "What have I learned?" and "Are there any more questions to investigate?")
3. Have students write all word banks and inquiries in their journals.
Check the Resources section of the teacher's guide for more reading suggestions, or the literature link on this site.