Which of the following is a group of jawless animals?

Which animal has a circular and sucking mouth located on the anteroventral side?

Which of the following is $NOT$ a characteristic of $Cyclostomata$?

Which of the following marine animals migrates to freshwater for spawning?

Statement $- I :-$ All living members of class $Cyclostomata$ are ectoparasites on some fishes.
Statement $- II :-$ $Cyclostomata$ have a sucking and circular mouth without jaws.

Circular and sucking mouth is found in . . . . . . .