Key out the Salmonid Species
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Key Out the Salmonid *Adapted from “2.4 Key It Out!” Students for Salmon Curriculum from the Nooksack Salmon Enhancement Association (http://www.n-sea.org/sfs-curriculum/) Objectives Become familiar with steelhead and the five Pacific Salmon species Use a dichotomous key to identify the six salmonids Understand how physical characteristic may impact a fish’s survival or ability to mate. Materials Pencil or Pen Dichotomous Key for each student Six salmon identification pages (PDF for printing or use the PowerPoint) Background After learning the differences between the six major salmonid species in the Puget Sound, students can now learn to distinguish them by appearance and reinforce what they have already learned. While distinguishing the fish, they’ll also be able to observe physical characteristics more closely and discuss their significance. These salmonids are each distinct species and have specific physical traits that help them survive and find mates to reproduce with. The images of the salmon in this activity are depictions of salmon when they are spawning, the time when some physical characteristics become more pronounced. Regardless of the sex of the fish, they both spend energy preparing their bodies to reproduce. Females must grow eggs and develop characteristics to contend with other females for nesting sites, while males will produce milt (fish semen) and often grow larger physical characteristics to compete with other males. Instructions Decide and use one of the following methods to organize the activity: a. By station; print the salmonid identification sheets—SINGLE SIDED AND IN COLOR, then place the salmonid identification sheets around the room as stations. Divide and start an equal number of students at each station, you can have them work as a group or individually. Give students 1-5 minutes (depending on the age group), to observe each identification sheet. Rotate the students clockwise until each group has visited the 6 different stations. b. By classroom display; view this PDF in ‘presentation’ display (view>present/full screen) and treat the pages with the salmon ID cards as slides. Have the class observe the slideshow in groups or individually. Advance each slide after 1-5 minutes (depending on the age group), until each of the 6 salmonid identification sheets has been observed by the class. Procedure: 1. Print and hand out a copy of the dichotomous key to each student or each group of students working together. 2. Explain to the class that as they rotate around the room (or observe the PowerPoint) they will use the dichotomous key to discover the identity of each fish. They will use the color images and the clues given to answer the questions on the key. Once they have followed the questions and answered them correctly, they will know the name of each fish. 3. Instruct the students to start at QUESTION 1 of the dichotomous key at each station (or PowerPoint slide). Explain that each question has two possible answers but that only one answer is true. 4. Once students determine which answer they think is true, they will follow that answer to the next step and repeat the process until they discover the name of the salmonid they are identifying. 5. Once they have identified the salmonid at the first station (or slide), or the allotted time is up, have the students write the name of the salmonid they identified at the bottom of their dichotomous key. 6. Have the students repeat steps 3-5 for until every student has visited each station, or, view every slide. Discussion Questions 1. What characteristics would you look for to identify an adult steelhead? 2. List some unique features of each salmon species. 3. Chum salmon are a silver color before they return to a shallow, fresh water stream to spawn where they are more vulnerable to predators on land. a. What do they look like when they are spawning as pictured? b. How would their appearance help them survive in a forest stream? 4. Male pink salmon, which are also sometimes called “humpies,” develop large humps on their back when they return to their fresh water stream to spawn. They often have to compete with other males to fertilize female eggs. a. Why would a large hump help them compete with other males? b. If pink salmon with larger humps are more successful at fertilizing female eggs, is it more likely that that their offspring will have large or small humps? NGSS: Performance Expectation: 3-LS4 From Molecules to Organisms: Structures and Processes 3-LS4-2. Use evidence to construct an explanation for how the variations in characteristics among individuals of the same species may provide advantages in surviving, finding mates, and reproducing. Scientific and Engineering Disciplinary Core Ideas Crosscutting Concepts Practices Use evidence to LS4.B: Natural Selection- Cause and Effect construct explanations. Sometimes the differences in Cause and effect characteristics between relationships are routinely individuals of the same identified and used to explain species provide advantages change. in surviving, finding mates, and reproducing. https://www.nextgenscience.org/pe/3-ls4-2-biological-evolution-unity-and-diversity Instructor Answer Key Station #1: Sockeye Salmon (Oncorhynchus nerka) Station #2: Chinook Salmon (Oncorhynchus tshawytscha) Station #3: Chum Salmon (Oncorhynchus keta) Station #4: Coho Salmon (Oncorhynchus kisutch) Station #5: Pink Salmon (Oncorhynchus gorbuscha) Station #6: Steelhead (Oncorhynchus mykiss) Identify Six Local Salmonid Species Use this key and the pictures provided to identify the different local salmonid species you have learned about. Instructions 1. Start at question 1 2. Read the question, then look at the picture and read the clues provided 3. Answer the question and follow the directions to the next step. 4. Go to the next step. 5. Repeat the process until you identify the fish. Question 1: Does the salmonid have spots on its caudal fin, dorsal fin, and back? 1a. Yes, the salmonid has spots on its caudal fin, dorsal fin, and back. Go to 2 OR 1b. No, the salmonid is missing spots in one or more of those locations. Go to 5 Question 2: Does the salmonid have spots covering its entire body, including on the belly and anal fin? 2a. Yes, the salmonid has spots on its entire body, and it has a slight rainbow coloring Answer = Steelhead (Oncorhynchus mykiss) OR 2b. No, the salmonid mainly has spots on its back, dorsal fin, and caudal fin. Go to 3 Question 3: Does the salmonid have spots over most of the caudal fin? 3a. Yes, the salmonids caudal fin is covered in spots. Go to 4 OR 3b. No, there are spots only on the top of the caudal fin, and the gums are white. Answer = Coho Salmon (Oncorhynchus kisutch) Question 4: Does the salmonid have large oval spots on its back and caudal fin as well as a hump on its back just behind its head (male only)? 4a. Yes, the spots on the salmon are large and oval, and there is a hump on the male’s back. Answer = Pink Salmon (Oncorhynchus gorbuscha) 4b. No, the spots are not large and oval, and there is no hump, but the gums are black. Answer = Chinook Salmon (Oncorhynchus tshawytscha) Question 5: Does the salmonid have an olive green body and dark red or purple bars on its side when spawning? 5a. Yes, the salmonid is olive green and has dark red or purple bars on its side. Answer = Chum salmon (Oncorhynchus keta) 5b. No, the salmonid has a red body when spawning. Answer = Sockeye salmon (Oncorhynchus nerka) ANSWERS: Write the correct name of the salmonid next to each station number. Station #1 ____________________________________________________ Station #2 ____________________________________________________ Station #3 ____________________________________________________ Station #4 ____________________________________________________ Station #5 ____________________________________________________ Station #6____________________________________________________ Station #1 Red body when spawning Average weight: 4-8 lbs Station #2 Dorsal Fin Caudal Fin Black/Gray Gums Largest of local Pacific Salmon Average weight: 10-24 lbs Station #3 Dorsal Fin Caudal Fin Red or purple vertical bars on body when spawning Average weight: 9-15 lbs www.fws.gov Station #4 Dorsal Fin Caudal Fin White Gums Average weight: 6-12 lbs www.fws.gov Station #5 Large oval spots on caudal fin and back, male develops hump when spawning Average weight: 2-5 lbs Station #6 Dorsal Fin Caudal Fin Dark spots covering the entire fish, slight rainbow coloring Average weight: 6-11 lbs Adult Chum Salmon Before Spawning: Photo courtesy of NOAA: https://www.fisheries.noaa.gov/species/chum-salmon Adult Pink Salmon with Large Hump: Photo courtesy of Washington Department of Fish and Wildlife: https://wdfw.wa.gov/fishing/salmon/pink.html Adult Pink Salmon with Large Hump: Photo courtesy of U.S. Fish and Wildlife Service: https://www.fws.gov/alaska/fisheries/fieldoffice/fairbanks/salmon/salmon%20ID%20chart.pdf Adult Pink Salmon with Small Hump: Photo courtesy of Timothy Knepp, U.S. Fish and Wildlife Service: https://news.orvis.com/fly-fishing/fish-facts-pink-salmon-oncorhyncus-gorbuscha .