Question

Bipinnaria larva is found in
A. Porifera
B. Coelenterata
C. Mollusca
D. Echinodermata

Answer 1

Hint: A bipinnaria is the first stage in the larval development of most starfish, and is usually followed by a brachiolaria stage.

Complete Answer:
This larva generally belongs to the phylum Echinodermata which is the largest phylum of the animal kingdom. It has the special feature of possessing 5 ciliated arms. They do not have any skeletal body support. They also have perioral and pastoral ciliary bandsThe arms that are present helps in swimming and they take their food in the form of planktons.

So the correct answer is option ‘D’ i.e; Echinodermata.

Additional information:
This type of larva is a characteristic of the class Asteroidea. Early Bipinnaria appears like a hypothetical dipleurula. It has an oval body without arms and ciliary bands for locomotion. It has a well developed alimentary canal for feeding and grows to become bipinnaria. They bear a close resemblance to the auricularia larva of Holothurians. The body of Bipinnaria larva is externally bilaterally symmetrical but subsequently, the internal structures assume asymmetry.

Note: They typically form the radial symmetry, which includes the starfishes and sea urchins. They generally appear like stars in structure. As it leads a free-swimming life, after a short period it transforms into a lecithotrophic brachiolaria larva.