Jawless vertebrates are placed in the group .........

Assertion: Cyclostomates are marine but migrate for spawning to fresh water.
Reason: After spawning,within a few days they die. Their larvae after metamorphosis return to the ocean.

Characteristic features of $Cyclostomata$ are

Which of the following characteristics does not apply to a hagfish?

Which of the following animals belong to the class Cyclostomata?

All the following statements are correct about $Petromyzon$ (Lamprey) except: