Sea - squirt is common name of :-

Options

A. Balanoglossus
B. Herdmania
C. Amphioxus
D. Ascidia

Answer

To solve the question "Sea-squirt is common name of:", we will analyze the options provided and identify the correct answer step by step.

### Step-by-Step Solution:

1. **Understanding the term "Sea-squirt":**
- The term "Sea-squirt" refers to a specific group of marine organisms that belong to the subphylum Urochordata.

2. **Analyzing the options:**
- **Option 1: Planoclosis**
- This is incorrect. Planoclosis is not associated with sea-squirts.

- **Option 2: Heart Mania**
- This option is misleading. Heart Mania does not refer to sea-squirts.

- **Option 3: Amphioxus**
- Amphioxus is commonly known as lancelets, which are not sea-squirts. They belong to a different subphylum (Cephalochordata).

- **Option 4: Acidia**
- This option is also incorrect. Acidia refers to a genus of sea-squirts, but it is not the common name for the entire group.

3. **Identifying the correct answer:**
- The correct common name for "Sea-squirt" is **"Ascidians"** which are part of the subphylum Urochordata. However, from the options provided, it seems that "Heart Mania" was incorrectly identified as the common name for sea-squirts in the transcript.

### Final Answer:
The common name for "Sea-squirt" is **Ascidians**.