AQUATIC VERTEBRATES 377 



Class B. Chondrichthyes (Gr. chondros, cartilage ; ichthys, fish ; the 

 skeleton is made of cartilage). Sharks, rays, skates. 



Class C. Osteichthyes (Gr. osteon, bone; ichthys, fish; the skeleton 

 is made chiefly of bone). Sturgeon, lungfish, perch, salmon. 



REVIEW QUESTIONS 



1. Explain the feeding habits of the lamprey eel and tell what these habits have 

 to do with commercial fishing. 



2. What evidence indicates a close relationship between the lamprey eel and 

 Amphioxus ? 



3. What is the function of the lateral line of fish? 



4. What is meant by ovoviviparous reproduction? 



5. Describe the two functions of the swim bladder. 



6. How does the flounder change its color pattern to blend with its surroundings ? 



7. Discuss protection of the young in fish. 



8. Would you think that the sea horse would lay as many eggs as the sturgeon ? 

 Give reasons for your answer. 



9. Describe the reproductive cycle in the salmon. 



10. What is the function of the internal ear of the fish? 



11. Describe the so-called "flight" of the flying fish. 



12. How does the freshwater minnow, Gambusia, fertilize its eggs? 



13. Tell the methods of protection used by the sting ray, sawfish, and electric eel. 



14. What is the function of the notochord in the lamprey? 



15. What is the function of the spiracle in the shark? 



