which one is not larval stage of flatworms ?

Options

A. Redia
B. Cercaria
C. Bipinaria
D. Miracidium

Answer

To determine which option is not a larval stage of flatworms, we will analyze each option provided in the question.

### Step-by-Step Solution:

1. **Understand the Question**: We need to identify which of the given options is not a larval stage of flatworms.

2. **Review the Options**:
- **Option 1: Radia** - This is a larval stage of certain trematode parasites, which develop in the body of a snail host. This means it is a larval stage of flatworms.
- **Option 2: Cercaria** - This is a free-swimming larval stage of a liver fluke, such as Fasciola hepatica. It is also a larval stage of flatworms.
- **Option 3: Biphenaria** - This is the first stage in the larval development of most starfish, not flatworms. Therefore, this is not a larval stage of flatworms.
- **Option 4: Miracidium** - This is a free-swimming ciliated larva that hatches from the egg and infects the first host. This is also a larval stage of flatworms.

3. **Identify the Correct Answer**: Based on the analysis, the correct answer is **Option 3: Biphenaria**, as it is not a larval stage of flatworms.

### Final Answer:
The option that is not a larval stage of flatworms is **Biphenaria**.

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