Question

if the characterustic is for a shark, put A. if its a bony fish characteristic, put B.

1. An air bladder is absent. 2. An air bladder is usually present. 3. Generally carnivorous, with a short intestine 4. Generally omnivorous, with a short or long intestine. 5. Gill filaments remain covered by operculum. 6. Gill slits, usually five pairs, open separately and directly to the exterior. 7. Operculum always absent. 8. Operculum with branchiostegal membrane always present. 9. The body is covered with cycloid or ctenoid or ganoid scales. The skin is soft. 10. The body is covered with minute and microscopic placoid scales, the skin is tough. 11. The endoskeleton is bony with amphicoelous vertebrae. 12. The endoskeleton is cartilaginous, with amphicoelous vertebrae 13. The head is dorsoventralily flattened. 14. The head may be dorsoventrally or laterally flattened. 15. The mouth is apical in position. 16. The mouth is ventral in position. 17. The tail is heterocercal, the vertebral column extending into the dorsal part of the caudal fin 18. The tail is homocercal, the vertebral column ends at the middle of the base of the caudal fin. 19. With a few exceptions, the young are hatched in an immature condition and undergo larval development 20. In some cases, development takes place within the oviducts and the young ones are born alive.

Answer 1

1. An air bladder is absent. - A

2. An air bladder is usually present. - B

3. Generally carnivorous, with a short intestine. - A

4. Generally omnivorous, with a short or long intestine. - B

5. Gill filaments remain covered by operculum. - B

6. Gill slits, usually five pairs, open separately and directly to the exterior. - A

7. Operculum always absent. - A

8. Operculum with branchiostegal membrane always present. - B

9. The body is covered with cycloid or ctenoid or ganoid scales. The skin is soft. - B

10. The body is covered with minute and microscopic placiod scales, the skin is tough. - A

11. The endoskeleton is bony with amphicoelous vertebrae. - B

12. The endoskeleton is cartilaginous, with amphicoelous vertebrae. - A

13. The head is dorsoventrally flattened. - A

14. The head may be dorsoventrally or laterally flattened. - B

15. The mouth is apical in position. - B

16. The mouth is ventral in position. - A

17. The tail is heteroceral, the vertebral column extending into the dorsal part of the caudal fin. - A

18. The tail is homoceral, the vertebral column ends at the middle of the base of the caudal fin. - B

19. With a few exceptions, the young are hatched in an immature condition and undergo larval development. - B

20. In some cases, development takes place within the oviducts and the young ones are born alive. - A