| 1. | Presence of vertebral column in adults |
| 2. | Ventral muscular heart |
| 3. | Open circulatory system |
| 4. | Paired appendages (fins or limbs) |
What is incorrect regarding cyclostomes?
| 1. | They are ectoparasites on some fishes |
| 2. | They have a circular mouth without jaws |
| 3. | Circulation is of open type |
| 4. | They are marine but migrate to fresh water for spawning |