A jawless fish, which lays eggs in freshwater and whose ammocoetes larvae after metamorphosis return to the ocean is?
1. Eptratretus
2. Myxine
3. Neomyxine
4. Petromyzon
Which one of the following pair of animals comprises 'jawless fishes'?
| 1. | Lampreys and eels |
| 2. | Mackerals and rohu |
| 3. | Lampreys and hagfishes |
| 4. | Guppies and hagfishes |