Which of the following organisms has tomaria and Auricularia as their larval forms respectively?

Options

A. Balanoglossus, Asterias
B. Asterias, Saccoglossus
C. Ophiura, Saccoglossus
D. Balanoglossus, Holothuria

Answer

To determine which organisms have tonaria and auricularia as their larval forms respectively, we need to analyze the options provided:

1. **Identify the larval forms**:
- **Tonaria** is a larval form associated with certain organisms, particularly some hemichordates.
- **Auricularia** is a larval form associated with echinoderms, specifically sea cucumbers.

2. **Examine the options**:
- **Option 1: Balenoglossus and Asterius**
- Balenoglossus has tonaria larvae.
- Asterius has brachiolaria larvae, not auricularia.
- This option is incorrect.

- **Option 2: Asterius and Sacroglossus**
- Asterius again has brachiolaria larvae.
- Sacroglossus is not known for auricularia larvae.
- This option is incorrect.

- **Option 3: Ophioria and Sacroglossus**
- Ophioria has ophiopluteus larvae.
- Sacroglossus does not have auricularia larvae.
- This option is incorrect.

- **Option 4: Balenoglossus and Holothuria**
- Balenoglossus has tonaria larvae.
- Holothuria has auricularia larvae.
- This option is correct.

3. **Conclusion**:
- The correct answer is **Option 4: Balenoglossus and Holothuria**, as Balenoglossus has tonaria larvae and Holothuria has auricularia larvae.