Question

Which of the following animal is devoid of notochord and nerve cord in it's adult stage?

• A. Herdmania
• B. Branchiostoma
• C. Balanoglossus
• D. All of the above

Answer 1

The correct option is A Herdmania

Herdmania is a hermaphrodite animal and belong to the group of chordates. They have oval body and long tail which shows the caudal fin. There is presence of notochord in the tail. The larva feed and then swims in search for an attachment. The larva needs advanced features for its free swimming existence. This Herdmania tadpole larva shows all chordate characters and possesses advanced characters as opposed to its adult. This larvae undergoes retrogressive metamorphosis and develops into adult Herdmania. There is loss of advanced characters when the larvae develops to form the adult.

Thus, the correct answer is option A.