Crawfish 101 Teacher Instructions

Transcription

1 Crawfish 101 Teacher Instructions Overview: The focus of this lesson is learning more about common Louisiana crawfish biology (i.e., body parts, species types/numbers, molting, exoskeleton strength and purpose, etc.) by observing a live specimen and making a simulated exoskeleton. Learning Objectives: The students will: Observe live crawfish specimens to identify the major external parts of the crawfish. Recognize the functions of the major external parts by watching crawfish walk, react to stimuli and swim. Simulate the molting process. Describe the process and purpose of molting. Materials List: 12-inch (30-centimeter) round balloons Antibacterial hand wipes (teacher provides) Clothespins Distilled water (teacher provides) Disinfectant wipes (teacher provides) Hot dog meat / wiener (teacher provides) Ice chest (teacher provides) Large bowl (teacher provides) Live crawfish (available from March through May) (teacher provides) Mass scale (teacher provides) Newspaper (teacher provides) Paper towels (teacher provides) Rulers Salt (teacher provides) Shoebox size plastic containers (teacher provides) Small bowls (teacher provides) Toothpicks Grade Levels: Upper elementary Subject Area: Science Duration: Three class periods Setting: Classroom Vocabulary: Abdomen Arthropod Carapace Cephalothorax Chelipeds (kee-luh-peds) Crustaceans Decapod Exoskeleton Invertebrate Omnivore Grade Level Expectations: Third Grade 1. Ask questions about objects and events in the environment (e.g., plants, rocks, storms) (SI-

2 E-A1) 6. Use the five senses to describe observations (SI-E-A3) 8. Select and use developmentally appropriate equipment and tools (e.g., magnifying lenses, microscopes, graduated cylinders) and units of measurement to observe and collect data (SI-E- A4) 12. Identify and use appropriate safety procedures and equipment when conducting investigations (e.g., gloves, goggles, hair ties) (SI-E-A7) 35. Compare structures (parts of the body) in a variety of animals (e.g., fish, mammals, reptiles, amphibians, birds, insects) (LS-E-A3) 57. Describe the interrelationships of living (biotic) and nonliving (abiotic) components within various ecosystems (e.g., terrarium, swamp, backyard) (SE-E-A1) Fourth Grade 1. Ask questions about objects and events in the environment (e.g., plants, rocks, storms) (SI- E-A1) 7. Use the five senses to describe observations (SI-E-A3) 9. Select and use developmentally appropriate equipment and tools (e.g., magnifying lenses, microscopes, graduated cylinders) and units of measurement to observe and collect data (SI-E- A4) 12. Use a variety of appropriate formats to describe procedures and to express ideas about demonstrations or experiments (e.g., drawings, journals, reports, presentations, exhibitions, portfolios) (SI-E-A6) 13. Identify and use appropriate safety procedures and equipment when conducting investigations (e.g., gloves, goggles, hair ties) (SI-E-A7) 41. Describe how parts of animals bodies are related to their functions and survival (e.g., wings for flying, webbed feet for swimming, etc.) (LS-E-A3) 53. Identify the habitat in which selected organisms would most likely live and explain how specific structures help organisms to survive (LS-E-C2) Fifth Grade 6. Select and use appropriate equipment, technology, tools and metric system units of measurement to make observations (SI-M-A3) 7. Record observations using methods that complement investigations (e.g., journals, tables, charts) (SI-M-A3) 23. Use relevant safety procedures and equipment to conduct scientific investigations (SI-M-A8) 23. Provide appropriate care and use safe practices and ethical treatment when animals are involved in scientific field and laboratory research (SI-M-A8) 34. Recognize the importance of communication among scientists about investigations in progress and the work of others (SI-M-B5) 27. Compare common traits of organisms within major ecosystems (LS-M-C3) Common Core State Standards: Third Grade 3-LS4-3. Construct an argument with evidence that in a particular habitat some organisms can survive well, some survive less well, and some cannot survive at all. [Clarification

3 Statement: Examples of evidence could include needs and characteristics of the organisms and habitats involved. The organisms and their habitat make up a system in which the parts depend on each other.] Fourth Grade 4-LS1-1. Construct an argument that plants and animals have internal and external structures that function to support survival, growth, behavior, and reproduction. [Clarification Statement: Examples of structures could include thorns, stems, roots, colored petals, heart, stomach, lung, brain, and skin.] [Assessment Boundary: Assessment is limited to macroscopic structures within plant and animal systems.] Vocabulary Definitions: Abdomen The back part of a crawfish s body. Arthropod Member of the phylum Arthropoda; invertebrate animal with an exoskeleton, a segmented body and jointed appendages. Carapace The thicker part of a crustacean s exoskeleton that covers the top and sides of its head and thorax (cephalothorax). Cephalothorax The front part of a crawfish s body that is made up of its head and thorax. Chelipeds (kee-luh-peds) The front two legs of a crawfish, which have large claws at the ends. Crustaceans Animals with a hard outer shell, such as crawfish, lobsters, crabs and shrimp (a subgroup of invertebrates). Decapod An order of crustaceans that have 10 feet (legs). Exoskeleton A crawfish s hard outer shell. Invertebrate Animal that does not have bones or a backbone. Omnivore An animal that eats both plant and animal material. Background Information: Crawfish are known by many names to Louisianans: crawfish, crayfish, crawdad and mudbug. This crustacean is similar to a lobster, but much smaller, ranging from 3 to 10 inches as an adult depending on the species and where it lives. Baby crawfish are about the size of a mosquito. There are approximately 500 species of crawfish in the world. More than 350 of these species reside in the streams and rivers of the United States, and 65 of those species are classified as endangered. More specifically, Louisiana is home to 36 different species of crawfish. Two of those species, the white river crawfish and the red swamp crawfish, are grown and distributed for human consumption. You can tell them apart because the red swamp crawfish has heavy and thick pincers. In contrast, the white crawfish has at least one long and one slender pincher. Red crawfish frequent

4 swamps, bayous and ditches, and white crawfish can be found in larger bodies of water that are deeper, such as lakes. Most crawfish live in fresh water and live to be 2 to 3 years old. They are mostly nocturnal and prefer cooler temperatures and a wet environment. If crawfish are out during the day, they often hide under rocks or logs. Their pincers, head and antennae face outside, so they can sense if danger is approaching and initiate protective measures. Observing a live crawfish helps students see how it can be classified as an arthropod and view how its outer parts help the crawfish function. Students probably have had experiences eating the crustaceans in one form or another, but providing this opportunity to get an up close and focused look at an important part of Louisiana s culture is beneficial to understanding how a crawfish interacts in Louisiana s wetlands. Crawfish Anatomy As crustaceans, crawfish have a hard outer exoskeleton that surrounds their bodies. The exoskeleton is made of calcium and chitin, which make it thin and flexible but also strong enough to protect their internal tissue. Crawfish outgrow their exoskeleton and go through the molting process about 11 times during their lifetime. This happens when the shell splits between the carapace and the abdomen. A crawfish eventually exits its old shell by flipping its tail repeatedly. After molting, crawfish remain without a shell for about 12 hours. The crawfish s exoskeleton is still very soft, which makes them vulnerable. When crawfish have reached their full size, they no longer molt. The body of a crawfish is divided into three sections: the head, thorax and abdomen. On a crawfish, the head and thorax are fused together, termed the cephalothorax. The carapace is the thicker part of a crustacean s exoskeleton that protects the top and sides of its cephalothorax. Crawfish have eyes on top of stalks that stick out of the top of their heads. They can see very well on land because they have compound eyes, like flies, which basically means their eyes are made up of many small eyes. They can move their eyes all around, too. Their excellent vision helps them to see danger right away when they are on land. Interestingly, crawfish can regenerate an eye if it gets hurt or lost. To breathe, crawfish have gills, like fish, to take oxygen from the water through their exoskeleton. The gills are located under the carapace. Crawfish also use their gills to get oxygen from the air, but the gills must be moist for this to work. Since crawfish like water, nighttime temperatures and mud, they may not be able to see as well in the dark, murky waters. So they use their antennae to sense things around them. Antennae aren t hair. Instead, the antennae are a sensory organ that contains small hairs that help crawfish sense things by feeling and smelling around them. To accomplish this, a crawfish has four antennae, two small and two long, on its head. A crawfish can regenerate its antennae, if needed. A crawfish s two claws, also called cheliped (pronounced kee-luh-ped), are used to grab, hold and tear food. Chelipeds are considered to be legs. The claws also are used as a defense mechanism, during the mating process, to build a crawfish s home and as an aggressive display where crawfish wave claws around, opening and shutting them in the air to scare off enemies. There are four pairs of walking legs that are used to move forward, backward and sideways. With the two chelipeds included, the crawfish has 10 total legs. This is why it is known as a decapod (deca = 10, pod = foot). Walking legs are jointed and are attached to the cephalothorax. If a crawfish loses a leg, it can regenerate another one. The abdomen ends in a tail fan, which is jointed and can be curled under itself very quickly. This helps the crawfish shoot backward very quickly in the water, making it hard to catch. The tail

5 also can be used as a swimming aid. Ten pairs of swimmerets are located below the crawfish s abdomen. These swimmerets may look like small legs, but their name hints to their use as a swimming aid. Advance Preparation: 1. Visit library to get informational books about crawfish (Some excellent books are cited in the resource section of this lesson.), encyclopedias, invertebrate or crustacean books with pictures and descriptions of crawfish and Why the Crawfish Live in the Mud book. 2. Purchase 1-3 pounds of live crawfish the day before the lesson is to be implemented. See the Lesson Safety and Tips section of this lesson (below) for directions on how to keep them alive and how to handle them. 3. Make copies of all student activity sheets. (See blackline masters.) a. Crawfish Parts and Functions (1 per pair of students) b. Crawfish Parts and Functions KEY (1 for teacher) c. Vocabulary (1 for teacher) d. Live Crawfish Exploration (1 per pair of students) e. Crawfish Comparison Chart (1 per pair of students) f. Crawfish Comparison Chart KEY (1 for teacher) g. Crawfish Quiz (1 per student) h. Crawfish Quiz KEY (1 for teacher) 4. Cut out the Vocabulary Cards. (See blackline master.) 5. Make the papier-mache mixture just prior to the class period on Day 2 of the procedure. a. Papier-mache paste recipe: 3/4 white glue to 1/4 water (If using a thick glue, go 1/2 and ½.) Lesson Safety and Tips: Maintaining live crawfish overnight and the next day Put crawfish in a container with a quarter-inch of distilled water. The water should only be high enough to keep their undersides wet. 2. Cut holes in the lid of the container for air. 3. The crawfish can remain alive for weeks if the distilled water is changed regularly and they are fed every few days. 4. Note: Do not release the crawfish into the environment after the activity. Instead, bring them back home and boil them for dinner or give them to someone who can. Crawfish Safety Tips 1. Have students wash hands before and after this exploration. 2. Pick up crawfish by placing the carapace (just above the walking legs) between the thumb and forefinger. Demonstrate this for students before you allow them to interact with the live crawfish. 3. You can ask the seafood vendor to bind at least one claw for you. That way students can at least view how one pincher works.

6 4. Even though crawfish have a hard exoskeleton, they also can be extremely delicate. Handle live crawfish with care. 5. Place the crawfish down in the bowl and on the table. Be careful not to drop them because a short fall can injure or even kill a crawfish. 6. Use only distilled water. 7. Do not keep the crawfish out of the water longer than 5 to 10 minutes. 8. Do not splash the water. 9. Do not pick up the container of water. Leave it on a flat surface. 10. Do not force or tease anyone who may be scared of touching the crawfish. 11. Only pick up a crawfish to place it where the exploration tells you. Do not pick up the crawfish and put it on someone or near someone s face or hands. 12. When working with crawfish, make sure students keep their hands away from their faces. Papier-mache 1. If the humidity is high, add less water (up to 1/4 less) to your papier-mache mixture. 2. Cover your project with no more than four layers of papier-mache. Two layers is a good amount for kids because they will probably overlap more than they should. 3. When allowing the papier-mache to dry, keep in a dry, well ventilated and well lit place. Otherwise, mold may grow. 4. Add salt to the recipe to prevent mold. 5. Let the papier-mache dry completely. 6. Look for the So Cool Science website: Insects Shedding Exoskeleton and Papier-mache Balloon Experiment in the reference section of this lesson. It models insect molting, but it also is helpful for the crawfish molting process. View the video ahead of time to make sure you guide students correctly through the balloon molting process. Procedure: Guiding Questions How does an exoskeleton protect a crawfish? What are the different purposes for those parts of a crawfish? Where does a crawfish live? How is the crawfish burrow made and what is it made of? How is a burrow important to a crawfish? Day 1: Crawfish Exploration Note: Make sure to get through steps 1-9 in 10 minutes to have time for the activity. 1. Familiarize yourself with crawfish by reading the background section and the safety and tip section of this lesson. Very important information is located in both of these places, and it must be adhered to for a safe and successful live crawfish observation. 2. Students should work in pairs for this activity. 3. Pass out the Crawfish Parts and Functions work sheet to each pair of students.

7 4. Ask them to look at the prediction chart carefully to see if they can name the parts that are being identified by the arrows. Make sure they are not writing on the sheet yet. Give them about two minutes. 5. Have them stop and look at you. One at a time, hold up the Vocabulary Cards for the parts of the crawfish. Have students quietly point to (not write) where they think each part is. (This process will work best, because through process of elimination; they will be able to make a better identification.) 6. Next, display all the vocabulary cards where students can see them, such as on a chalkboard tray or taped on the wall. 7. Discuss with the students where they decided the parts were located. Use the Crawfish Parts and Functions KEY to make sure students have identified the part names correctly. 8. Give the students three to five minutes to predict the function of each part. They will fill in the actual function after the activity. 9. Tell them to set the Crawfish Parts and Functions work sheet to the side for now. They will use it as a resource during the exploration. 10. Pass out the Live Crawfish Exploration work sheet to each pair of students. 11. Read the Crawfish Safety Tips (included earlier in this lesson) to the students. 12. Tell the students they will be observing live crawfish today to explore crawfish anatomy and behavior. Tell them they must maintain respect for the live creature during this opportunity. a. Make sure they do not horseplay with or hurt the crawfish in any way. b. Make sure they demonstrate care and respect for the crawfish. 13. Pass out all the materials needed for the exploration (rulers, scales, one crawfish per clear container with water that just covers the crawfish but not submerges it and paper towels for water cleanup or to dry hands after handling the crawfish). 14. Allow the students 30 minutes to complete this activity. 15. Regularly squirt or pour distilled water on the crawfish to keep them hydrated. 16. Walk around the classroom and closely observe the students. If you stop to talk or question pairs of students, make sure you stand so you can still watch the rest of the class. This will help maintain the safety of the class and the crawfish. 17. Make sure students remain on task and strictly follow the safety and tips you reviewed. 18. When time is up and students have completed the observation, make sure to have students clean up their areas and put the supplies back where they belong. Put live crawfish back in ice chest. 19. Have students clean their areas with a disinfectant wipe and then wash their hands thoroughly. 20. As students return to the classroom, have students look back at the predictions they made on the Crawfish Parts and Functions and discuss what they have learned with their partners before a class discussion occurs. 21. As a class, have students discuss thoughts about what the actual function of each labeled part is. Review the answers (KEY) with the students to make sure they have the correct answers. Give them time to write the correct answers on their sheets.

8 Day 2: Exoskeleton Preparation and Comparison Chart 1. Prepare papier-mache paste just prior to the class period (see Advance Preparation section). 2. Pass out a balloon, newspaper strips, a small bowl with papier-mache paste and a clothespin to each pair of students. 3. Leave enough supplies for you to make a teacher model. 4. Show each of the following steps and allow the students to perform each step after you demonstrate it. a. Blow up the balloon to about the size of a grapefruit. Have students complete the task. b. Twist the end of the balloon closed, but do not tie it. Instead, secure the twisted end with the clothespin. Have students complete the task. c. Dip a newspaper strip in the paste mixture and stick the strip on the balloon. Repeat this with a second paper strip, placing it on the balloon so it overlaps half of the first strip. Have students complete the task. d. Explain that you will continue adding strips, overlapping each one until most of the balloon is covered with paper. Try to only put two layers of strips. Make sure to leave an opening around the end of the balloon (clothespin side). Have students complete the task. 5. Leave overnight to dry. (See safety and tips section of this lesson to help with this task.) 6. Pass out the Crawfish Comparison Chart for students to complete individually. 7. Read the directions with the students and review the crab example that s included. 8. Give students about 10 minutes to complete this task. Day 3: Molting Exoskeleton (Papier-mache) 1. Make sure the paper from yesterday s papier-mache project is completely dry. A firm paper shell will cover the balloon. 2. Discuss with the students how the firm shell represents the exoskeleton of the crawfish and the balloon represents the soft body of the crawfish. Refer back to the background information. 3. Remove the clothespin but don t let the air out of the balloon. 4. Gently blow into the balloon, making it slightly larger. a. Ask the students what they think will happen? (When you blow up the balloon, the uncovered section of the paper shell separates slightly.) b. Ask the students why they think this happens. (The balloon and hard paper shell represent an arthropod such as the crawfish. Its body is covered by an exoskeleton because it is an invertebrate without a backbone. This exoskeleton does not grow with the crawfish. As the rest of its body grows, the exoskeleton becomes too small. A new exoskeleton begins to form under the old one.) c. Explain that when the old exoskeleton becomes too small for the growing crawfish, blood and sometimes air or water inside the insect is forced into the thorax by the contraction of muscles in the abdomen. This splits the exoskeleton, usually along the middle of the back side. The crawfish repeatedly moves its tail to help shed the skin and then crawls out. This process of shedding the exoskeleton is called molting. Crawfish molt about 11 times in their lives, but this process stops when they reach the adult stage.

9 5. Demonstrate how to pull the balloon out. Use one hand to gently hold the exoskeleton and tug the balloon with the other hand. Don t rip the paper on purpose to get it out. Instead, slowly tug on the balloon in different directions until the balloon slides out. The paper may get torn slightly from the tugging. Just be gentle and patient, and it will happen. A crawfish has to do the same thing with its tail s movement helping it exit the old exoskeleton. a. When the crawfish first crawls out of its old exoskeleton, its new exoskeleton is still moist and flexible like the wet paper strips when they were put on the balloon. The crawfish gulps in air or water to expand the flexible exoskeleton before it dries and hardens like the paper strips. The dried, stretched exoskeleton provides growing space until the next molt. 6. Show the balloon that represents the fragile crawfish. Since the crawfish has lost its exoskeleton, it has nothing to protect it from predators or the elements. a. What do you think the crawfish does now? (It hides in its burrow.) 7. Allow students to reflect in their science journals about: a. What it means to have no bones but to have an exoskeleton. b. What happens if part of the exoskeleton rips during molting? c. Where crawfish go after they have molted? d. What types of threats the crawfish might be susceptible to right after molting? 8. Pass out the Crawfish 101 Quiz to individual students. 9. Collect and grade the quiz, using the Crawfish 101 Quiz KEY. Extension Ideas: Wikihow: Catch live crawfish by building a crawfish trap! If available, show students live examples of both the red swamp crawfish and the white river crawfish. Students can compare and contrast them. See LSU AgCenter: Crawfish Biology in the resource section of this lesson plan for a link to a detailed comparison and contrast. Blackline Masters: Crawfish Parts and Functions Crawfish Parts and Functions KEY Vocabulary Live Crawfish Exploration Crawfish Comparison Chart Crawfish Comparison Chart KEY Crawfish Quiz Crawfish Quiz KEY Resources: Blaxland, Beth. Crabs, Crayfishes and Their Relatives (2002). Macmillan: Australia

10 Downing, Johnette. Why the Crawfish Lives in the Mud (2009). Pelican Publishing Co.: Gretna, La. (Summary: When crawfish takes advantage of crab s generosity, his trickery costs him his friendship.) Education.com Balloon Molting Lesson (adapted). Foss Web: Crawfish Resources Grimm, Phyllis W. Crayfish (2001). Learner Publication Co.: Minneapolis: Minn. Kalman, Bobbie. The Life Cycle of a Crayfish (2007). Crabtree Publishing Co.: New York, N.Y. Louisiana Public Broadcasting: Crawfish Observation Louisiana Seafood News: Crawfish Picture for Media Use LSU Agricultural Center: Crawfish Biology Microsoft Office Clip Art: Clip Art Images So Cool Science: Insects Shedding Exoskeleton and Papier-mache Balloon Experiment Virginia Cooperative Extension: The Control of Burrowing Crayfish in Ponds

11 Name Date Crawfish 101 student activity sheet Vocabulary Swimmerettes Cheliped/pincer Abdomen Walking legs Compound eye Short and long antennae Wetlands Program provided by LSU AgCenter

12 Name Date Crawfish Parts and Functions Chart Crawfish 101 student activity sheet Part Name: Predicted Function: Actual Function: Part Name: Predicted Function: Actual Function: Part Name: Predicted Function: Actual Function: Part Name: Predicted Function: Actual Function: Part Name: Predicted Function: Actual function: Part Name: Predicted Function: Actual Function: Wetlands Program provided by LSU AgCenter

13 Name Date Crawfish Parts and Functions Chart Crawfish 101 student activity sheet KEY Part Name: Abdomen Predicted Function: Answers may vary Actual Function: Moving backward quickly, swimming Part Name: Compound eye Predicted Function: Answers may vary Actual Function: Seeing in all different directions in color Part Name: Long and short antannae Predicted Function: Answers may vary Actual Function: Sensory organs for feeling, tasting Part Name: Swimmerettes Predicted Function: Answers may vary Actual Function: Aids in swimming Part Name: Walking legs Predicted Function: Answers may vary Actual Function: Walking in different directions, picking up food Part Name: Chelipeds/pincers Predicted Function: Answers may vary Actual Function: Holding food in place, burrowing Wetlands Program provided by LSU AgCenter

14 Name Date Live Crawfish Exploration Anatomy Identification 1. Inspect live crawfish to find each part from the chart. 2. Complete the following information. Body Part Compound Eyes Walking legs Pincers/chelipeds Abdomen Swimmerettes Antennae Number Counted Behavior 1. A stimulus is something you do that excites an organism or part, so you can note a reaction or function. Crawfish 101 student activity sheet Measure and Observe Length (in centimeters): Mass (in grams): Color(s) Smell(s) Sound(s) What do you think the crawfish will do if you reach for it? Do not do it yet. Predict. Reach for the crawfish, but do not touch it. What did it do? 2. Focus on these specific stimuli. Write the results in the response column. Note: Be gentle with the crawfish. Do not pull or poke roughly. You may want to pick up the crawfish, as instructed, to perform this part of the exploration. Body Part Stimulus Response Walking legs Abdomen Swimmerettes Antennae Light touch Light touch Light touch Light touch 3. Observe the tail fin. Does it bend? If it does, that means it is jointed. What part of your body is jointed? Explain how that one of your body parts is similar to the tail fin of the crawfish. How is it different? 4. Place the crawfish on the table. What did it do? Observe how it moves and what body parts are used to accomplish different tasks. Wetlands Program provided by LSU AgCenter

15 Name Date Functions Crawfish 101 Live Crawfish Exploration (continued) Pick up your crawfish and gently rub the exoskeleton of the crawfish. Make sure not to rub near the pincers. What does it feel like? Why does it feel like that? Gently squeeze the cephalothorax and then squeeze gently nearer to its tail? Do those places feel the same or different? Explain. What do you think is the function of the cephalothorax? Try the different methods of feeding the crawfish that are shown to the right. What does the crawfish do when you try to feed it? When it is eating the meat, what do you observe? Be specific. Crawfish Feeding Methods Place the crawfish in the water and put meat in the water next to it. Place a piece of meat on one of its free pincers. Dip meat on a toothpick into the water and place it near the crawfish s mouth so the water runs into its mouth. Place the crawfish back in the clear container of water. Observe it. What did it do? What parts were used? Join another pair of students. Put your crawfish facing their crawfish on the table. What do they do? Wetlands Program provided by LSU AgCenter

16 Name Date Crawfish Comparison Chart Crawfish 101 student activity sheet Directions: After observing the crawfish in class today, compare and contrast the crawfish with other animals found in Louisiana. Write one similarity and one difference for each. Do not mention color in what you write. Instead, use parts of the anatomy and the functions of each. You may use jots. One example has been completed for you. Similarity: Both have claws to help capture food Difference: Body shape is wider for crab Similarity: Difference: Similarity: Difference: Similarity: Difference: Similarity: Difference: Similarity: Difference: Wetlands Program provided by LSU AgCenter

17 Name Date Crawfish Comparison Chart Crawfish 101 student activity sheet-key Directions: After observing the crawfish in class today, compare and contrast the crawfish with other animals found in Louisiana. Write one similarity and one difference for each. Do not mention color in what you write. Instead, use parts of the anatomy and the functions of each. You may use jots. One example has been completed for you. (Possible answers given. Students answers may vary.) Similarity: Both have claws to help capture food Difference: Body shape is wider for crab Similarity: Both have legs for walking Difference: Does not have claws Similarity: Both have a tail Difference: Lives only in the water Similarity: Both invertebrates Difference: can fly Similarity: Grabs its food Difference: Has feathers; can fly Similarity: Has more than two walking legs Difference: Creates a web Wetlands Program provided by LSU AgCenter

18 Name Date Crawfish 101 student activity sheet Crawfish 101: Quiz Directions: Read the following selection carefully. If the water dries out of a nearby ditch, a crawfish will dig a hole called a burrow in the mud next to the ditch. It builds a mud tower that looks like a smokestack on top of its burrow. The burrow goes down into the ground like an ant tunnel. The crawfish then lives inside the moist, cool burrow under the tower until it rains. When it rains heavily, the tower will wash away, but the crawfish is safe deep inside the burrow. The crawfish stays in its home until the storm has ended. Directions: Read each statement and determine if it is true or false. Refer to the selection above for eviden to support your answer. (2 points each) 1. Crawfish build their own homes. 2. Crawfish live near water. 3. Crawfish enjoy hot, dry weather. 4. Crawfish build their homes and towers from grass and leaves. Directions: Use the selection above to answer the following short answer questions. 5. What do you think the crawfish will do after a heavy rain ends? Explain by providing evidence from the selection to support your answer. (2 points) 6. Which parts of the crawfish s outer anatomy will be used to build the burrow? Choose two parts of the anatomy and explain how each will be used to help build the burrow. (4 points) 7. What does molting mean for an arthropod? Explain how the crawfish will use its burrow during the molting process. (2 points) Directions: Fill in the blanks. (1 point each blank) Crawfish are decapods, meaning they have how many legs? Crawfish are along with shrimp, crabs and lobsters. In Louisiana, there are at least two other terms for crawfish. Those are: Crawfish are omnivores. This means they eat both and. The hard outer shell of the crawfish is called the. Wetlands Program provided by LSU AgCenter

19 Name Date Crawfish 101 student activity sheet-key Crawfish 101: Quiz Directions: Read the following selection carefully. If the water dries out of a nearby ditch, a crawfish will dig a hole called a burrow in the mud next to the ditch. It builds a mud tower that looks like a smokestack on top of its burrow. The burrow goes down into the ground like an ant tunnel. The crawfish then lives inside the moist, cool burrow under the tower until it rains. When it rains heavily, the tower will wash away, but the crawfish is safe deep inside the burrow. The crawfish stays in its home until the storm has ended. Directions: Read each statement and determine if it is true or false. Refer to the selection above for eviden to support your answer. (2 points each) 1. Crawfish build their own homes. True 2. Crawfish live near water. True 3. Crawfish enjoy hot, dry weather. False 4. Crawfish build their homes and towers from grass and leaves. False Directions: Use the selection above to answer the following short answer questions. 5. What do you think the crawfish will do after a heavy rain ends? Explain by providing evidence from the selection to support your answer. (2 points) Rebuild the tower because it washed away. 6. Which parts of the crawfish s outer anatomy will be used to build the burrow? Choose two parts of the anatomy and explain how each will be used to help build the burrow. (4 points) (Some possible answers include, although answers may vary: Claws grabbing and placing mud, burrowing into the ground and moving mud to the side; Legs walking in and out of the burrow; Eyes to see what crawfish is doing; and Tail for pushing mud out of the way) 7. What does molting mean for an arthropod? Explain how the crawfish will use its burrow during the molting process. (2 points) Molting occurs when an invertebrate has outgrown its exoskeleton. It eventually will shed the exoskeleton during the molting process. After a crawfish sheds its exoskeleton, it will stay inside its burrow for protection, since it lost the protection of its exoskeleton. Directions: Fill in the blanks. (1 point each blank) Crawfish are decapods, meaning they have how many legs? 10 Crawfish are crustaceans along with shrimp, crabs and lobsters. In Louisiana, there are at least two other terms for crawfish. Those are: crawdad, mudbug, crayfish. Crawfish are omnivores. This means they eat both meat and plants. The hard outer shell of the crawfish is called the exoskeleton. Wetlands Program provided by LSU AgCenter