Question Detail
Question
Consider the following statements regarding Balanoglossus: 1. The eggs are fertilized outside the body and the development is indirect. 2. Full grown tornaria larva has three ciliated bands, two apical plates and a pair of pigmented eye-spots. 3. Tornaria larva is a free-swimming larval stage. Which of the statements given above are correct?
Correct Answer
Option D is the correct answer.
Detailed Explanation
All three statements are correct for Balanoglossus (acorn worm). Fertilization is external, and development is indirect via a free-swimming tornaria larva. The full-grown tornaria larva is characterized by three ciliated bands (prototroch, metatroch, telotroch), two apical plates (anterior sense organs), and a pair of pigmented eye-spots.
Hint
This hemichordate has a larval form similar to that of echinoderms, reflecting their common ancestry.