Question

Select the incorrect statement about cyclostomes?

• A. Elongated body bearing 6-15 pairs of gill slits
• B. Body is devoid of scales and paired fins.
• C. Circulation is of closed type.
• D. Circular mouth with jaws and teeth.

Answer 1

The correct option is D Circular mouth with jaws and teeth.

Vertebrates are divided into two divisions on the basis of presence of the jaws. Agnatha are groups lacking jaws and Gnathostomes are groups having jaws. Class Cyclostomata falls under the division Agnatha. Thus, Cyclostomata are marine in habitat lacks jaws so it has a circular shaped mouth with a sucking type of mouth part with teeth. Body is elongated and devoid of scales with unpaired fins. They have 6-15 pairs of gill slits and a closed circulatory system. Cyclostomata includes animals like Petromyzon (lamprey) and Myxine (hagfish).