ELEMENTARY SCIENCE PROGRAM Math, Science & Technology Education. A Collection of Learning Experiences on CRAYFISH CATTARAUGUS-ALLEGANY BOCES GRADE 4

Transcription

1 ELEMENTARY SCIENCE PROGRAM Math, Science & Technology Education A Collection of Learning Experiences on CRAYFISH CATTARAUGUS-ALLEGANY BOCES GRADE 4

2 TABLE OF CONTENTS Unit Overview...3 Format & Background Information Learning Experience 1 - Getting Started...8 Learning Experience 2 - Crayfish Habitat Learning Experience 3 - Behavior of Crayfish...11 Learning Experience 4 - Parts, Parts, and More Parts Learning Experience 5 - Feeding...14 Learning Experience 6 - Measure the Crayfish...15 Learning Experience 7 - Social Order Crayfish Student Assessment And Answer Key More Ideas...21 Inquiry and Process Skills...22 Glossary Teacher References

3 Unit Overview CRAYFISH GRADE 4 This unit provides the opportunity for students to observe the structures and behavior of crayfish. Students will identify physical characteristics, reaction to stimuli, feeding habits, and territorial behavior. Science skills emphasized in Crayfish are observing, predicting, discussing, describing, measuring, gathering and interpreting data. Scheduling This unit may take from six to eight weeks to complete depending upon the goals of the teacher and interests of the students. Use of the section included in this manual called More Ideas may extend the time span of this kit. Materials to be obtained locally: Caution Please make one student activity book for each student. chart paper water felt tip markers food for crayfish notebooks (fish, fruit, vegetables, folders earthworms, hamburger, etc.) paper towel nail polish (assorted colors) metric ruler Remind students to wash their hands after handling any of the materials in the kit. Students should be reminded that crayfish are living organisms and should not be mistreated. Crayfish should not be left unattended on desktops or in plastic jars. About the Format Each learning experience is numbered and titled. Under each title is the objective for the learning experience. Each learning experience page has two columns. The column on the left side of the page lists materials, preparations, basic skills processes, evaluation strategy, and vocabulary. The evaluation strategy is for the teacher to use when judging the student s understanding of the learning experience. The right column begins with a Focus Question which is typed in italicized print. The purpose of the Focus Question is to guide the teacher s instruction toward the main idea of the learning experience. The Focus Question is not to be answered by the students. The learning experience includes direction for students, illustrations, and discussion questions. These discussion questions can be used as a basis for class interaction. 3

4 A Student Assessment has been included in the Teacher s Manual and the Student Activity Manual. If you do not want the students to have the assessment beforehand, remove it from the Student Activity Manual before printing a class set of the student manuals. Background Information Crayfish History Crayfish belong to the phylum of invertebrates called Arthropoda, which means, joint footed. Crayfish belong to the class of Arthropoda called Crustacea. Lobsters, brine shrimp, and isopods also belong to the crustacea class. There are more than 200 crayfish species in the United States and less than 12 species are native to New York State. Crayfish are cold-blooded animals. This means that their body temperature changes with the surrounding temperature. In the North, they burrow into the mud to hibernate for the winter and emerge again in the spring. Crayfish are found in freshwater streams, ponds, and lakes. They hide under rocks, in crevices, in plants, or in burrows. The crayfish is a bottom dwelling animal. It faces the entrance of its hiding place with pincers ready and antennae waving while swimmerets and maxillae keep water moving over the gills. It attacks prey and defends itself from predators in this position. If the shelter is opened or crayfish is exposed, it darts backwards by fanning its tail and flexing its abdomen. Crayfish become active at night. They look for food such as water plants, tadpoles, insect nymphs, or dead fish. Crayfish Anatomy The body of the crayfish is divided into three sections: the head, the thorax, and the abdomen. Each region is made up of body segments. The head and thorax are fused together forming the cepalothorax. The abdomen consists of six flexible, jointed segments. The first five segments each have a pair of swimmerets attached. In males, the first two swimmerets near the thorax are fused, elongated, and used during mating. In females, the first pair of swimmerets is lacking. The remaining four pairs of swimmerets are more developed in females because they are used to carry eggs. The sixth segment of the abdomen is the bold tail, and it consists of five parts. The four fanshaped parts, the uropods, are hinged and located on either side of the center part of the tail, or the telson. The crayfish uses its tail to swim backwards, maintain balance, and females use their tail to protect eggs. Crayfish can grow to 15 cm in length, but many are much smaller. As crayfish grow, they go through a molting process. When the crayfish molts, the outer covering called the exoskeleton, is shed. New crayfish shells are soft so they are vulnerable to attack by predators and other crayfish. Soft-shelled crayfish should be separated from the other crayfish in the classroom habitat until their shells have hardened. Young crayfish molt several times a year. Before molting, a new, soft exoskeleton grows beneath the old one. The old exoskeleton splits between the carapace and the abdomen. The crayfish slowly pulls its cephalothorax backwards and out of the carapace. The pincers 4

5 and walking legs pull free. Finally, the abdomen and tail are pulled forward and freed from the exoskeleton. The crayfish can replace lost appendages and parts of its eyes. Younger crayfish have a greater ability to regenerate lost parts than older crayfish. A lost appendage is partially formed at the next molt and increases in size each time it molts. Respiration The gills on the crayfish are projections in a gill chamber along both sides of the thorax. The gill chamber is covered by the carapace, but is open to water flow at both ends and just above the walking legs. There are seventeen pairs of gills used to obtain dissolved oxygen from the water. The second small pair of maxillae near the mouth moves back and forth to draw water forward over the gills. If the percentage of dissolved oxygen in the water is low, crayfish use their swimmerets to aid in water circulation. Senses Crayfish use their senses to gather information about their environment. Most of its body is sensitive to touch, especially the pincers, walking legs, mouth parts, underside 5

6 of the abdomen, and edge of the tail. These areas contain tactile hairs, which are connected to sensory nerves. The sense of taste and smell are in the hairs of the antennules, antennae, and mouth parts. If a food stimulus is placed near the crayfish, it will turn toward the stimulus and move its mouth parts rapidly. Crayfish have two sets of antennae. At the base of the smaller antennae are tiny openings. These small sacs, containing sensory hairs, mucus, and sand grains, serve as an organ of equilibrium. When the crayfish moves or tilts its body, the action of gravity on the grains of sand produces stimuli through the hairs to a nerve that leads to the brain. This movement of the body changes the stimulus to the brain so the crayfish can right itself. The compound eyes of a crayfish are mounted on stalks that allow the crayfish to retract its eyes when in danger or move them about to provide better vision. Each compound eye is made up of many microscopic facets, which act like many small eyes. Since the compound eye sees many images of the object almost exactly alike, the crayfish notices any change in motion in one of the images. Reproduction The fused swimmerets on the male crayfish s abdomen assist in sperm transfer to the female crayfish. The female s paired oviducts open at the base of the second pair of walking legs. The four pairs of swimmerets on the female are larger than the male s and are used to carry the eggs and young crayfish. Compare swimmerets on the abdomen of the male and female. See picture above. In the spring, when the water warms, the crayfish becomes active. The female cleans her abdomen and swimmerets, then a slimy secretion is produced from the glands on the swimmerets. Sperm being held in her receptacles fertilizes eggs. The eggs stick to the secretion on her swimmerets. After the eggs are attached to the swimmerets, they hang from them. The eggs will hang in this location for five to eight weeks until they hatch. Each young is a miniature crayfish and is approximately 4 mm long. They appear transparent. The young crayfish molt six or more times during the first two months of life. By the second molt, the young break free from their mother. 6

7 During the first month, the young crayfish stay close to their mother for protection. They then go on their own. By late autumn, they are 35 to 50 mm long and are shaped like the adults. They will be able to mate the following spring. Crayfish can live from one to four years. If you receive a female with eggs in your classroom, isolate her and do not disturb her. She will eat the eggs if disturbed. Leave her alone for several weeks and do not feed her. Observe her daily. If eggs float in the water, they have died. The water in the crayfish habitat should be changed. Crayfish Habitat The plastic container in which the supplies for this kit come in will act as the habitat for the crayfish. The habitat for the crayfish should be set up at least one-two days before the crayfish arrive. Place the habitat near an electrical outlet so an air pump can be used in it. Keep the habitat in a location where it will be out of direct sunlight. Crayfish live best in rooms where the air temperature is C. The gravel for the habitat is included in the kit. Wash the gravel with water to remove silt and contaminates. Spread the washed gravel on the bottom of the plastic container. Add water to the container until there is a depth of two to three centimeters. The water added to the habitat should have been left out for hours so chlorine can dissipate. Keep a bucket of water that has been out for two or three days in the classroom throughout the unit. This aged water can be used to replenish the water in the habitat as it evaporates. The aged water should also be used to fill the clear plastic jars when students remove the crayfish from the habitat. Place the air stone near the center of the habitat. Place the flower pots randomly in the habitat. The flower pots act as hiding places for the crayfish. The water in the habitat must be changed if it becomes contaminated. An indication that the water has become contaminated is a cloudy appearance or an unpleasant odor. Food should never be allowed in the habitat. If the water does become contaminated, remove the crayfish, dump the water & rinse the gravel. Then wipe down the container, air line tubing, and air stone with paper towels. Do not use soap or any other cleaners. Feeding The crayfish are to be fed in the clear plastic jars filled halfway with water. Crayfish are omnivores, therefore, they eat both plants and animals. Crayfish will eat corn and small pieces of fish. The ideal size portion of food for the crayfish is about the size of a kernel of corn. Feeding the crayfish once or twice a week is sufficient. Crayfish can live a month without eating. After crayfish have been fed, they can return to the habitat. Discard the water and the food left in the plastic jar. Release of Crayfish The crayfish provided for this kit are indigenous to New York State. Therefore, they can be released into a local fresh water pond or stream. 7

8 Learning Experience 1: Getting Started Objective: Students will use their background knowledge to create a KWHL chart on crayfish. Materials: For the class: Crayfish coupon Book - Crayfish by Phyllis Grimm Chart paper* Felt-tip markers* Notebooks* Folders* *provided by teacher Preparation: Read background information on pages 4-7. When you are ready for the crayfish to be sent to your classroom, send the coupon that is in the kit to the company. Allow 2-3 weeks for delivery. Notify the school office that you will be receiving live perishable materials and that you should be notified as soon as they arrive. Each student should obtain a notebook and folder with pockets to hold their activity sheets for this unit. Conduct this lesson several days before the crayfish arrive. Basic Skills Development: Discussing Brainstorming Evaluation Strategy: Students will use their background knowledge to create a KWHL about crayfish. Vocabulary: crayfish crustacean What do we know about crayfish? Using the KWHL strategy, students will explore their knowledge about crayfish and then expand on it throughout the unit. Brainstorm what the students already know about crayfish. Record their ideas on a class-size K-W-H-L chart. Ask students what they would like to know about crayfish and record their ideas under the want to know column. Now that the students have decided what they want to know, they need to think about how they are going to find out the answers to the questions they have. After the hands-on activities, maintaining journals, and discussions, students can then record information in the what we learned and still want to learn column. This process can also be done in cooperative groups where students gather information in small groups then share their ideas with the class. Read Chapter 1 of the book Crayfish by Phyllis Grimm to introduce the unit to students. What do we know KWHL Strategy What do we know about crayfish? What do we want to know How are we going to find out? What we learned and still want to learn. 8

9 Learning Experience 2: Crayfish Habitat Objective: Students will research the habitat of the crayfish and then create a classroom habitat for the crayfish. Materials: For the class: 12 live crayfish Large plastic container used as kit box Airline tubing Air stone Gravel 5 flowerpot houses Bucket Water* *provided by teacher Preparation: Read background information on page 7. Basic Skills Development: Discussing Creating Models Describing Interpreting Data Evaluation Strategy: Students will research the habitat of the crayfish and contribute to the development of the classroom crayfish habitat. Vocabulary: crayfish habitat research How should we take care of our crayfish? Ask students to provide information about a crayfish s habitat from their own experiences seeing or catching crayfish. Develop a word web with students in which they use their experiences to describe a crayfish habitat. Crayfish Habitat Give students the opportunity to research any additional information about what is needed to create a healthy environment for crayfish. Use this research information when putting together the crayfish habitat. The habitat for the crayfish should be set-up two days before the crayfish are scheduled to arrive. The large plastic container used as the kit box should be used to create the habitat. Spread the washed gravel on the bottom of the container to the depth of approximately 1-2 centimeters. Water is then added to the container. If tap water is used, allow the water to stand one or two days. The chlorine will then dissipate from the tap 9

10 Learning Experience 2 continued Page 2 water. The water depth in the habitat should reach approximately two to three centimeters. Water will need to be changed when it becomes cloudy or has an odor. (Remember: leave tap water out for at least 24 hours before adding it to the habitat.) Place the five flowerpot houses in the habitat. These flowerpots act as hiding places for the crayfish. Keep a bucket of water that has been out for two or three days in the classroom throughout the unit. This aged water can be used to replenish the water in the habitat as it evaporates. The crayfish habitat should be placed near an electrical outlet for the small air pump with air stone. The pump aerates the water. Place the crayfish in the pool as soon as they arrive. Once crayfish arrive, discuss the care and handling of the crayfish with the class. A chart of the ways to care for and handle crayfish can be posted near the crayfish habitat. 10

11 Learning Experience 3: Behavior of Crayfish Objective: Students will observe their crayfish and create a journal of crayfish behaviors to understand how it functions in its own environment. Materials: For each group of three students: 3 Crayfish Student Activity Books Crayfish 3 double lens magnifiers Paper towel* Nail polish (assorted colors)* For the class: Crayfish habitat *provided by teacher Preparation: Read background information on page 6. Basic Skills Development: Discussing Observing Describing Evaluation Strategy: Students will identify typical behaviors of their crayfish and journal this behavior. Vocabulary: crayfish behavior observe How does your crayfish behave? Assign a group of three students to observe a particular crayfish. Since all the crayfish look the same, ask students to dry the shell of their crayfish and put a small dot of nail polish on its back so they can identify it later. (Too much nail polish can kill the crayfish). Allow the nail polish to dry. Students are to observe their crayfish s behavior in the classroom habitat. Student groups are to make a journal entry of the behaviors of their crayfish. A sample of a journal entry page is found on the activity sheet for Learning Experience #3 in the Crayfish Student Activity Book. Student s can make daily or weekly journal entries of their crayfish s behavior. See sample questions listed below to focus student observations. Student groups can compare their crayfish s behavior with that of another group s crayfish. Discussion Questions: Does your crayfish like to be out in the open or under the flower pots? How does your crayfish move? In what direction does your crayfish move the fastest? What happens when you move your hand toward your crayfish? Do crayfish like light or dark places? 11

12 Learning Experience 4: Parts, Parts, and More Parts Objective: Students will identify the body parts of the crayfish and describe their function. Materials: For each group of three students: 3 Crayfish Student Activity Books Crayfish 3 double lens magnifiers Clear plastic jar Water* For the class: Crayfish habitat Book-Crayfish by Phyllis Grimm *provided by teacher Preparation: Read background information on pages 4-7. Allow the students time to feel comfortable picking up the crayfish. Basic Skills Development: Discussing Observing Describing Evaluation Strategy: Students will identify the major parts of the crayfish and describe their importance. Vocabulary: crayfish antenna walking legs claws identify swimmerets abdomen cephalothorax pincer male female carapace maxilliped telson uropod What are the parts of the crayfish? Ask students to observe the parts of their crayfish carefully and to identify as many parts as they can. Students are to draw a detailed picture of the top view of their crayfish and the bottom view of their crayfish on the activity sheet for Learning Experience #4 in the Crayfish Student Activity Book. Students may need to put their crayfish in the clear plastic jar to observe the underside of the crayfish more easily. Be sure to add aged water to the jar before placing crayfish inside. Discussion Questions: How many legs does a crayfish have? How many legs have claws? Do all the crayfish have the same number of body parts? What other body parts have you found? Provide students with the drawn diagram of a crayfish on page 2 of the activity sheet for Learning Experience #4 in the Crayfish Student Activity Book, and have them look for parts that they may have missed in their first observation. Students can then label the parts of the diagram. Discuss with students the function of each part of the crayfish. Be sure to distinguish between the walking legs and swimmerets of the crayfish. Chapter 2 of the book Crayfish by Phyllis Grimm describes the parts of the crayfish and includes various photographs of crayfish. 12

13 Learning Experience 4 continued Page2 Session 2: Ask each student groups to pick up their crayfish or place their crayfish in the plastic jar. Go around to each group s crayfish and tell each group the sex of their crayfish, but do not tell them how you know. Have student groups with a male crayfish pair up with a group that has a female crayfish. List the differences between the male and female crayfish on the chalkboard. Students are to then record if their crayfish is male or female on page 1 of their activity sheet for this learning experience. Students should also know how they are able to make that identification. Chapter 5 of the book Crayfish by Phyllis Grimm further describes how the female carries and protects her eggs. It also provides information on the life cycle of the crayfish. 13

14 Learning Experience 5: Feeding Objective: Students will identify the food preferences of the crayfish and describe typical feeding behaviors. Materials: For each group of three students: 3 Crayfish Student Activity Books Crayfish Clear plastic jar 3 double lens magnifiers Food - pieces of fish, fruit, vegetables, earthworms, hamburger, etc.* Water* For the class: Crayfish habitat Book - Crayfish by Phyllis Grimm Chart paper* Felt tip markers* *provided by teacher Preparation: Read background information on page 7. Crayfish should be fed in the plastic jars or another small container separate from the crayfish habitat. This prevents the contamination of the habitat. Discard the water placed in the jar after feeding. Basic Skills Development: Observing Discussing Comparing Interpreting Data Evaluation Strategy: Students will describe typical feeding behaviors of crayfish. Vocabulary: diet contaminate preference What does your crayfish eat? Students are to feed bits of food to their crayfish and observe its preferences. Some crayfish may eat only once or twice a month so students may need to share the crayfish that are eating. If the crayfish does not eat a particular food, try a different food or another way of presenting the food. Discussion Questions: What senses does your crayfish use to find food? How does the crayfish eat its food? What parts of the crayfish are used in feeding? How do the mouth and mouth parts work? How does the crayfish hold its food? Does the mouth react differently to different foods? Have the students record their observations on their journal page for this learning experience. The journal page is found on the activity sheet for Learning Experience #5 in the Crayfish Student Activity Book. Student groups can report the food preferences of their crayfish and create a class chart of the preferences. Through research, students can then compare the diet of their crayfish in the classroom habitat to that of the crayfish in its natural habitat. Chapter 3 of the book Crayfish by Phyllis Grimm describes what Dinner Time is like for the crayfish. The author includes information on how crayfish find and capture their food and the types of food they eat. 14

15 Learning Experience 6: Measure the Crayfish Objective: Students will measure the length, width, and mass of the crayfish and will compare these measurements using a table and graph. Materials: For each group of three students: 3 Crayfish Student Activity Books Crayfish Metric ruler* For the class: 4 balance bases 4 balance stands 4 balance arms 4 balance pins 4 jars of gram cubes 8 baskets 8 paper clips Modeling clay *provided by teacher Preparation: A demonstration of how to the use the double pan balance may be necessary. Basic Skills Development: Measuring Observing Comparing Gathering and Organizing Data Evaluation Strategy: Students will gather data on the size of their crayfish using various measurement tools and compare the classroom data. Vocabulary: mass volume length width property What size is our crayfish? Students are to use various tools to measure their crayfish. Student groups will use a metric ruler to find the crayfish s length and width. Then use the double pan balance and the gram cubes to find the mass of the crayfish. Student groups will need to share the four double pan balances provided. Students can record their data on their activity sheet for Learning Experience #6 in the Crayfish Student Activity Book. Student groups can then trade crayfish to check each other s measurement results. Once students record their data, graph the results. Pages 2-4 of the activity sheets allow students to graph the data for each group s crayfish and compare results. Crayfish will need to be identified on the graph by number or letter. Discussion Questions: What group s crayfish has the greatest length? Width? What group s crayfish has the greatest mass? What is the average length of the crayfish in our class? Average width? What is the average mass of the crayfish in our class? 15

16 Learning Experience 7: Social Order Objective: Students will observe crayfish interactions and will describe/compare the relationships through their journals. Materials: For each student: 3 Crayfish Student Activity Books For the class: 8 crayfish 2 rectangular plastic containers 4 flowerpots Gravel Book - Crayfish by Phyllis Grimm Water* *provided by teacher Preparation: Crayfish, which are handled frequently, will not act naturally so this learning experience should not be done in the main pool. Basic Skills Development: Observing Comparing Discussing Describing Predicting Evaluation Strategy: Students will observe and journal the social behavior of a number of crayfish of the same sex. Vocabulary: social behavior prediction observation dominant How can we find out how crayfish act with each other? Place four marked male crayfish in one of the rectangular plastic container with water, gravel, and two flower pots, and place four marked female crayfish in the other rectangular plastic container with water, gravel, and two flower pots. Group the class into two groups. One group should observe the female crayfish and another group should observe the male crayfish. Observe the crayfish when they are first placed in the rectangular plastic container and again a few hours later. Ask students to journal their observations on the activity sheet for Learning Experience #7 in the Crayfish Student Activity Book. Discussion Questions: Where are the crayfish now? What is their behavior like? Do you notice any distinguishable characteristics of any particular crayfish? Before observing the crayfish for a second day, ask students to make a prediction of how they think the behavior of the crayfish will change or not change. Then observe the crayfish again and record observations on page 2 of the activity sheet. Discussion Questions: Where are the crayfish today? Allow students to observe the crayfish behavior for a few days and then discuss their observations. 16

17 Learning Experience 7 continued Page 2 Discussion Questions: Did two crayfish ever share a flower pot? How did one crayfish get another one out of its pot? Did the same crayfish always return to the same pot? Begin to change this habitat. Predict what will happen if only one pot is left in the basin. Then remove all pots except one. Observe for a few days. Ask students to, again, journal their observations on page 3 of their activity sheet. Discussion Questions: Is one crayfish stronger than the others? If the most dominant crayfish takes over the flowerpot after several days, remove that crayfish. Does the next crayfish in the social order take over, and so on? Return the crayfish to the original habitat one at a time (every two days), but in reverse order of dominance. Observe the crayfish and discuss. Read the final chapter (chapter 5) of the book Crayfish by Phyllis Grimm titled Enemies. This chapter not only provides information on animals that prey on crayfish, it also describes how crayfish interact with each other. 17

18 Name: Crayfish Student Assessment Date: Directions: Read the question carefully and answer based on your knowledge about crayfish. Circle the correct answer. 1. The lifecycle of the crayfish begins by: a. being born alive b. hatching out of an egg c. being carried in the pouch of its mother d. developing from a larva 2. When being approached from the front, a crayfish will often respond by: a. hissing at the creature b. lunging towards its attacker c. retreating backwards d. holding perfectly still 3. The exoskeleton of a crayfish functions mainly to: a. help it grow b. protect it from predators c. keep its organs intact d. keeps the crayfish from drying out 4. A crayfish uses its to defend itself. a. uropod b. pincers c. eyes d. tail 5. In their natural habitat, crayfish are usually most active: a. in the morning b. during the day c. at night d. all the time 6. The female crayfish uses her swimmerets to a. protect and carry her eggs b. carry food c. scare off predators d. attract males when mating 18

19 Crayfish Assessment Page 2 7. Crayfish are classified as based on their eating habits. a. herbivores b. carnivores c. omnivores d. producers 8. An animals natural home is called its a. cheliped b. gills c. invertebrate d. habitat 9. A hard shelled water animal is called a(n) a. plankton b. maxilliped c. crustacean d. mammal 10. An animal that does not have a backbone is referred to as a(n) a. vertibrate b. invertibrate c. herbivore d. carnivore 11. Label the parts of the crayfish. List of words: Cephalothorax, Antennule, Abdomen, Telson, Uropod, Swimmerets, Walking Legs, Carapace, Pinier Cheliped, Antenna, Maxilliped, Eye 19

20 Crayfish Student Assessment Key 1. B 2. C 3. B 4. B 5. C 6. A 7. C 8. D 9. C 10. B 20

21 MORE IDEAS Language Arts Ask student groups to write a story about the day in the life of their crayfish. Write different types of poetry on crayfish. Research the difference between crayfish and lobsters and/or crabs and create a venn diagram of the similarities and differences. Make a list of other crustaceans and ask students to report on their habitat, feeding habits, and body structures. Book Suggestions: Clovis Crawfish Series Books by Mary Alice Fontenot Bugs, Slugs, & Crayfish - Right Before Your Eyes by John R. Wiessinger Math Create word problems using the crayfish data collected. Social Studies Map out the local ponds, streams, rivers in your area. Science Take your class to a nearby pond and catch your own crayfish. Compare these crayfish with those in your school habitat. Are the new crayfish different in any way? Are they more aggressive? What effect does light have on crayfish? Have students design experiments to test their predictions. Find out which crayfish is the strongest. Ask students to devise ways to test the strength of the crayfish. Tapered pieces of plasticine can be used. Students can measure the thickness of the plasticine nipped off by the crayfish s pincer. Is the largest crayfish always the strongest? Graph results. 21

22 INQUIRY AND PROCESS SKILLS Classifying: Collecting Data: Communicating: Generalizing: Formulating Hypotheses: Identifying Variables: Inferring: Interpreting Data: Making Decisions: Manipulating: Measuring: Observing: Predicting: Replicating: Using Numbers: Arranging or distributing objects or events in classes according to some method or system. Obtaining visible or measurable information which illustrates a specific situation. Displaying or transmitting information to others. Drawing general conclusions from information. Constructing a proposition or assumption of what is thought likely to be true based on reasoning, which serves as a tentative testable theory. Recognizing characteristics of objects or events which are constant or change under different conditions. Making a statement based on reasoning to explain an observation. Analyzing information that has been collected and organized and describing apparent patterns or relationships in the information. Choosing an alternative from among several and basing the judgment on defendable reasons. Handling or treating materials, equipment, or procedures skillfully and effectively. Making quantitative observations by comparing to a standard. Becoming aware of an object or event by using any of the senses to identify properties. Making a forecast or estimate of what future events may occur. Performing acts that duplicate demonstrated symbols or patterns. Stating and applying mathematical rules or formulas to calculate or compute quantities from basic measurements. 22

23 GLOSSARY Abdomen: Antenna: Behavior: Carapace: Cephalotharax: Claws: Contaminate: Crayfish: Crustacean: Diet: Dominant: Female: Habitat: Identify: Length: Male: Mass: the elongated portion of the body of an orthropod located behind the thorax. It is usually segmented. a sensory organ found in pairs on heads of organisms, including insects & crustaceans. the way an animal or object reacts under certain conditions. a thick hard case or shell that covers the body, especially the back of an animal such as the crayfish or crab. fused head and thorax of many crustaceans. an appendage used for grasping in crayfish, crabs and other invertebrates, pincers. to make impure, unclean, especially by mixing impurities into it. a freshwater crustacean with large claws. an anthropod with several pairs of jointed legs, hard protective outer shell, two pairs of antennas, and eyes at the end of stalks the food an animal consumes. relating to a single animal or animal species that is greater in number, power or importance within a community or over a specific period. belonging to the sex that produces eggs or young. a natural or controlled environment in which a plant or animal lives. to recognize something and name what it is. the distance along an object from end to end. belonging to the sex that produces sperm to fertilize female eggs. the amount of matter an object contains. 23

24 Maxilliped: Observe: Observation: Pincer: Prediction: Preference: Research: Social: Swimmerets: Telson: Walking legs: Width: Uropod: specialized feeding appendages located behind the maxillae on the heads of crustaceans. to watch someone or something attentively, especially for scientific purpose. the record of observing natural phenomenon and noting developments. front claws of some crustaceans used for grasping objects. forming an opinion of what will happen based on previous knowledge or experience. opportunity to choose a course of a time that is considered more desirable than another. investigation into a subject in order to discover facts. relating to the way animals in groups behave or interact. an abdominal appendage on some crustaceans that is adapted for swimming, and in females, for carrying eggs. the last segment of an arthropod. legs used by crayfish for movement. the distance from one side or edge to the other. either of a pair of flat appendages on the last abdominal segment of a crustacean. 24

25 TEACHER REFERENCES Levenson, Elaine Teaching Children About Life and Earth Science Media Library Call the media library to order media materials and to check on new materials that are available. The number to be reached is (716) Websites: