Question

Which one of the following is a larval form of jelly fish?

• A. Amphiblastula
• B. Ephyra
• C. Redia
• D. Rhabditiform

Hint:

Associate key larval forms with their phyla:

\textbf{Cnidaria (Jellyfish):} Planula, Ephyra
\textbf{Porifera (Sponges):} Parenchymula, Amphiblastula
\textbf{Platyhelminthes (Flukes):} Miracidium, Sporocyst, Redia, Cercaria
\textbf{Nematoda (Roundworms):} Rhabditiform, Filariform \end{itemize} Knowing these associations is very helpful for matching-type questions.

Answer 1

The Correct Option is B

Step 1: Concept Overview:
This question assesses understanding of invertebrate life cycles, specifically identifying the jellyfish larva (Phylum Cnidaria, Class Scyphozoa).

Step 2: Option Analysis:
- Amphiblastula: Larval stage of sponges (Phylum Porifera).
- Ephyra: Juvenile jellyfish medusa, produced asexually via strobilation of the scyphistoma polyp. It matures into the adult jellyfish.
- Redia: Larval stage of flukes (Phylum Platyhelminthes, Class Trematoda), developing in a snail host.
- Rhabditiform: First-stage larva of many nematodes (Phylum Nematoda), such as hookworms and roundworms.

Step 3: Conclusion:
The ephyra is the larval/juvenile form associated with the jellyfish life cycle. Therefore, option (B) is correct.