Question

Write a brief account on cyclostomata.

Answer 1

Cyclostomata is a group of agnathans that comprises the living jawless fishes: the lampreys and hagfishes. Both groups have jawless mouths with horny epidermal structures that function as teeth, and branchial arches that are internally positioned instead of external as in jawed fishes.The name Cyclostomata means "round mouths".It was named by Joan Crockford Beattie.

Answer 2

Answer:

All living members are ectoparasite on some fishes they have an elongated body 6-15 pair of gill slite for respiration. They have a sucking and circular mouth without jaws their body is devoid of scale and paired fins. Cranial and vertebral column are carteliginious circulation is of closed type.

Example - petromyzon.