A phylum exclusively marine is

Options

A. Coelenterate
B. Porifera
C. Protozoa
D. Echinodermate.

Answer

To answer the question "A phylum exclusively marine is," we will analyze each of the provided options step by step to identify which one is exclusively marine.

### Step 1: Analyze the first option - Coelenterata
- Coelenterata, also known as Cnidaria, includes organisms like jellyfish, corals, and sea anemones.
- They are primarily aquatic, but they can be found in both marine and freshwater environments.

**Hint:** Consider whether the organisms in this phylum can live in both marine and freshwater habitats.

### Step 2: Analyze the second option - Porifera
- Porifera, or sponges, are mostly marine organisms, but there are also species that inhabit freshwater environments.

**Hint:** Think about the habitat diversity of sponges and whether they are limited to marine environments.

### Step 3: Analyze the third option - Protozoa
- Protozoa are a diverse group of single-celled organisms that can be found in various environments, including freshwater, marine, and even soil.

**Hint:** Reflect on the ecological versatility of protozoans and their ability to thrive in multiple habitats.

### Step 4: Analyze the fourth option - Echinodermata
- Echinodermata includes starfish, sea urchins, and sea cucumbers.
- This phylum is exclusively marine, meaning all members of this group live in oceanic environments.

**Hint:** Consider the defining characteristics of echinoderms and their habitat specificity.

### Conclusion:
After analyzing all the options, we find that the only phylum that is exclusively marine is **Echinodermata**. Therefore, the correct answer to the question is:

**Echinodermata**