Give the characteristics of the following with examples :
Class Cyclostomata

Explanation

(i) These are marine animals having fish-like body with bilate ral symmetry.
(ii) They have jaw-less mouth provided with sucker (suctorial mouth).
(iii) Their skin is soft and without any scale.
(iv) Paired appendages are absent.
(v) Endoskeleton is cartilagenous.
(vi) Most of the animals are ectoparasites. e.g. Petromyzon, Myxine, etc.