Question

Cephalochordate Branchiostoma possesses

• A. Laterally compressed spindle shaped body
• B. Caudal fin
• C. Dorsal and ventral fins
• D. All of the above

Answer 1

The correct option is D All of the above

Branchiostoma is a small lancet-shaped organism and belongs to the phylum Chordata and sub-phylum Cephalochordata. Branchiostoma posses tapered anterior and posterior ends (spindle-shaped body). The body is laterally flattened (flat from side to side). It has a snout at the anterior end and a caudal fin at the posterior end. Towards the dorsal or upper side of the body, it has a 'dorsal fin' which extends entirely along the mid-dorsal line up to the caudal fin ( which is broader). The 'ventral fin' is shorter than the dorsal fin. It extends from the caudal fin up to the atriopore, a median opening which expels water from the pharynrx entering through the mouth.

So, the correct answer is 'All of the above'.