Question

Cyclostomata are fish _____. made of cartilage without a jaw made of bone

Answer 1

Lamprey and hagfish are jawless fish, with skeletons composed of cartilage. They do not have scales and are considered primitive fish. They are in the superclass cyclosystoma.

Answer 2

Answer: The correct answer for the blank is-

without a jaw.

Cyclostomata is a group of jaw-less fishes ( belonging to the super-class agnatha) under the phylum chordata.

It possesses the lampreys and hag-fishes, which are living jawless fishes.  Both these groups possess mouths without jaws. Their epidermal structures are sharp, which act as as teeth, and branchial arches are located internally (unlike jawed fishes, which have externally positioned branchial arches).

Thus, without a jaw is the right answer.