Physalia is commonly known as:

Options

A. sea fan
B. sea pen
C. jelly fish
D. Portuguese man o war

Answer

**Step-by-Step Solution:**

1. **Identify the Scientific Name**: The question asks for the common name of "Physalia." Physalia is a genus of marine organisms.

2. **Research Common Names**: The common name associated with Physalia is "Portuguese man of war." This name comes from its appearance, which resembles a ship from Portugal.

3. **Understand the Structure**: Physalia has a distinctive structure that looks like a helmet or a sail, which floats on the water's surface. This structure is often compared to the helmets worn by Portuguese soldiers.

4. **Recognize Its Characteristics**: Physalia is known for its long tentacles that contain venom, which can be harmful to small fish and even humans.

5. **Conclusion**: Therefore, the common name for Physalia is "Portuguese man of war."

**Final Answer**: Physalia is commonly known as the Portuguese man of war.

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