Which of the following phylum have organisms that are exclusively marine ?

Options

A. Aschelminthes
B. Echinodermata
C. Arthropoda
D. Annelida

Answer

To solve the question of which phylum has organisms that are exclusively marine, we can follow these steps:

### Step 1: Understand the Question
We need to identify which phylum consists entirely of marine organisms. This means that all members of the phylum must live in marine environments.

### Step 2: Analyze the Options
We will evaluate each phylum provided in the options to determine if they contain only marine organisms.

### Step 3: Evaluate Each Phylum
1. **Acoelomates (Aeschylmanthes)**:
- This phylum includes various organisms, but not all are marine. Some can be found in freshwater or terrestrial environments.
- **Conclusion**: This option is incorrect.

2. **Echinodermata**:
- This phylum includes organisms such as sea urchins, starfish, and sea cucumbers.
- All members of this phylum are exclusively marine and live in oceanic environments.
- They also exhibit radial symmetry.
- **Conclusion**: This option is correct.

3. **Annelida**:
- This phylum includes segmented worms, which can be found in marine, freshwater, and terrestrial environments.
- **Conclusion**: This option is incorrect.

### Step 4: Final Conclusion
Based on the analysis, the only phylum that contains organisms that are exclusively marine is **Echinodermata**.

### Answer
The correct answer is **Echinodermata**.

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