Dichotomous+Key+Assignment

Name __________________________ Date_________________ Dichotomous Key Assignment Part 1: Use the images provided in the Dichotomous Key Assignment, information on fish anatomy, and the dichotomous key to correctly identify the species of fish. Marine Fish Key 1. a. The fish has a body like a snake. Go to #2 b. The fish does not have a body like a snake. Go to #3 2. a. The fish has a beaklike mouth. Anquilla rostrata (American eel) b. The fish has a suction cup type mouth. Petromyzon marinus ( Lamprey) 3. a. The fish has eyes on the same side and a flattened body. Go to #4 b. The fish does not have eyes on the same side and no flattened body. Go to #5 4. a. The fish has a forked tail. Hippoglossus Stenolepsis (Halibut) b. The fish does not have a forked tail. Paralichthys Albigutta (Gulf Flounder) 5. a. The fish has placoid scales. Go to #6 b. The fish does not have placoid scales. Go to #7 6. a. The fish has a pointed head. Squalus acanthias ( Dogfish shark) b. The fish does not have a pointed head. Sphyrna mokarran (Hammerhead shark) 7. a. The fish’s body is full moon shaped with a little caudal fin. Mola mola (Ocean sunfish) b. The fish’s body is not distinctly moon shaped and has a highly visible larger caudal fin. Go to #8 8. a. The fish’s body is club shaped like a baseball bat. Anarhichas lupus (Wolffish) b. The fish’s body is not club shaped like a baseball bat. Go to #9 9. a. There is evidence of a chin barbell. Go to #10 b. There is no evidence of a chin barbell. Go to #13 10. a. The caudal fin is not notched or only just barely notched. Go to #11 b. The tail fin is decidedly notched. Go to #12 11. a. The fish has 3 distinct dorsal fins (top side). Gadus morhua (Atlantic Cod) b. The fish has 2 distinct dorsal fins. Merluccius merluccius (Hake) 12. a. The lower jaw extends beyond the upper jaw. Theragra chalcogramma (American Pollock) b. The lower jaw does not extend beyond the upper jaw. Melanogrammus aeglefinus (Haddock) 13. a. The fish has finlets Go to #14 b. The fish does not have finlets. Go to #15

14. a. The dorsal fins are widely separated. Scomber scombrus (Mackeral) b. The dorsal fins are not separated widely. Thunnus maccoyii (Bluefin Tuna) 15. a. The fish has a small adipose fin. Osmerus mordax (American Smelt) b. The fish does not have a small adipose fin. Alosa pseudoharengus (Alewife) Put your answers here. List the scientific name for each species of fish. (5pts each - total 80 pts) 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. __________________________