Coelenterate without medusoid stage in life cycle is

Options

A. Obelia
B. Aurelia
C. Physalia
D. Metridium.

Answer

To solve the question "Coelenterate without medusoid stage in life cycle is," we will analyze the options provided and determine which organism does not have a medusoid stage in its life cycle.

### Step-by-Step Solution:

1. **Understand the Life Cycle of Coelenterates**:
- Coelenterates (Cnidarians) typically have two main life forms: the polyp and the medusa. The polyp is usually sessile (attached to a surface), while the medusa is free-swimming.

2. **Analyze the Options**:
- **Option 1: Obelia**:
- Obelia is a colonial hydrozoan that exhibits both polyp and medusa stages in its life cycle. Therefore, it does have a medusoid stage. This option is incorrect.

- **Option 2: Aurelia**:
- Aurelia, commonly known as moon jelly, also has a distinct medusa stage. This option is incorrect as well.

- **Option 3: Fusilier (Portuguese Man of War)**:
- The Portuguese Man of War is a colonial organism that has a medusa stage. Thus, this option is also incorrect.

- **Option 4: Matridium**:
- Matridium, known as the sea anemone, primarily exists in the polyp form and does not have a medusoid stage in its life cycle. This makes it the correct answer.

3. **Conclusion**:
- The coelenterate without a medusoid stage in its life cycle is **Matridium**.

### Final Answer:
The correct answer is **Matridium**.

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