LAB ACTIVITY: HOW DOES TEMPERATURE AFFECT THE RATE …



LAB ACTIVITY: HOW DOES TEMPERATURE AFFECT THE RATE OF RESPIRATION IN FISH?Background: In this laboratory activity we will change the temperature of the water that a fish is in and determine what impact, if any, this has on the breathing (respiration) rate of the fish. Counting gill cover movements is a way to calculate respiration rates in fish. Fish breathe by taking water in through the mouth and forcing it over the gills when the mouth closes. An oxygen-carbon dioxide exchange occurs. Then the operculum opens to allow the carbon dioxide-rich water to exit. By counting gill cover movements, students are getting an idea of a fishes' response to an ecological change. Respiration rates will typically increase as dissolved oxygen concentration decreases. An increase in water temperature means a decrease in dissolved oxygen available for the fish to breathe from the water. Materials: GoldfishTank WaterTupperware BowlMedium beaker, 600ml ThermometerTimer or clockIceHot water Procedure:Bring all materials to your lab table.Bring the empty beaker to the aquarium containing the goldfish & fill it ~ 2/3 full with aquarium water.Use a thermometer to measure the temperature of the water in your medium beaker (fish bowl.)The starting temperature needs to be 20 °C. If needed, add warm water until the water is 20 °C.Place a 600ml beaker with the fish into the Tupperware bowlDetermine baseline data:Take the temperature of the water in the beaker & record on the data table Allow your goldfish some time to calm down (this may take several minutes)Count respirations (by looking at either the opening/closing of the mouth or the opercula) for one minute & record on the data table on the back of this page. DO NOT add ice or hot water directly to the goldfish beaker!Determine warm water experimental data:Fill an empty beaker with warm water from the water bath at the front of the room. Place your fish beaker in the plastic bowl & add warm water to the tupperware bowl; this will slowly increase the temperature inside the beaker. Once the temperature inside the fish beaker has increased ~5 degrees Celsius count respirations for one minute. Record data in the data table. Repeat, making sure to not go above 30°CDetermine cold water experimental data:Pour out any water from your Tupperware bowl & fill it approximately 1/3 full with tap water. Add 1-2 pieces of ice to slowly into the Tupperware bowl to lower the temperature of the water until the temperature inside the fish beaker has decreased ~5 degrees Celsius from the original temperature (20°C)Count the number of times your goldfish breathes in one minute. RECORD in the data table.Repeat making sure not to go below 10°C and RECORD in the data tableClean up all materials & place your gold fish in the “rest” tank to recover.Data:200?????????????????????195?????????????????????190?????????????????????185?????????????????????180?????????????????????175?????????????????????170?????????????????????165?????????????????????160?????????????????????155?????????????????????150?????????????????????145?????????????????????140?????????????????????135?????????????????????130?????????????????????125?????????????????????120?????????????????????115?????????????????????110?????????????????????105?????????????????????100?????????????????????95?????????????????????90?????????????????????85?????????????????????80?????????????????????75?????????????????????70?????????????????????65?????????????????????60?????????????????????55?????????????????????50?????????????????????45?????????????????????40?????????????????????101112131415161718192021222324252627282930Figure 1: Observations of fish with in different temperaturesTemperatureYour fishFish 2Fish 3Average (Your fish + Fish 2 + Fish 3) ÷ 320 °C room temp15 °C cool10 °C colder25 °C warm30 °C warmerFigure 2: Observations - Line GraphPlot separate lines to show the average breathing rate of fish at each of the different temperaturesLabel each line with a different colorAdd a title that includes the dependent and independent variables Title _________________________________________________________________________________________ `BreathsPerMinutesTemperature °CPrelab----Answer the following questions before completing the lab procedure:What is the purpose of this lab activity? __________________________________________________________________________________________________________________________________________________________________________ Are fish warm-blooded or cold-blooded animals? ____________________________________________________________________________________How do external temperatures affect cold-blooded animals? ____________________________________________________________________________________How do external temperatures affect warm-blooded animals? ____________________________________________________________________________________What do you think will happen as you increase/decrease the temperature of your goldfish’s water? __________________________________________________________________________________________________________________________________________________________________________ Restate what you said above as a hypothesis? (If…. Then… Because)__________________________________________________________________________________________________________________________________________________________________________What is the independent variable (the factor that you are controlling)? ____________________________________________________________________________________ What is the dependent variable (the factor that changes with the independent variable’s changes) ___________________________________________________________________________________What are the variables we have to keep as constants (factors that are the same for everyone) _____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________What is our control group data (normal environment for the fish)? ____________________________________________________________________________________ANSWER THE FOLLOWING QUESTIONS AFTER COMPLETING THE LAB PROCEDUREBased on your data what is the relationship between respiration and temperature in fish?Based on the graph data, what do you think is the relationship between fish behavior and temperature?Does the data in the graph support or contradict your hypothesis? What other factors (besides temperature) may have affected the rate?What do you think happens to the activity of fish in cold climates during the winter months? Why do you think cold-blooded animals, like the goldfish, change their breathing rate when the surrounding temperature changes?How do you think this might explain the results of the experiment? Observations: (Restate each of your observations; be sure to use numbers AND units from data you collected!!)___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________Conclusion: (ONE sentence about whether your hypothesis was or was not correct based on the data)________________________________________________________________________________________________________________________________________________________________________________________________________Analysis (2-3 Paragraphs): Use your data to summarize the effect of temperature of on fishSupport any statements you make with data from your graph or data tableBe sure to state at least one source of error experiments are not perfect and we can always improve!! State what you would do differently. ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________Three More Questions (What you still want to know)____________________________________________________________________________________________________________________________________________________________________________________________________________________________________Extra Credit--- Design an experiment that will test how a fish's respiration rate is affected by light. Explain your design. You may wish to draw a picture of your set-up. Include how you will change the environment and what you will be measuring. ................
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