Which of the following is not applicable for members of the phylum Echinodermata?

Options

A. Habitat - Exclusively marine
B. Symmetry - Adults are radially symmetrical
C. Body system- Presence of canal system due to the folding of the body wall
D. Development - Indirect

Answer

To determine which of the following options is not applicable to members of the phylum Echinodermata, we will analyze each option based on the characteristics of this phylum.

### Step-by-Step Solution:

1. **Understanding Echinodermata**:
- Echinoderms are marine animals that include species such as starfish, sea urchins, and sea cucumbers. They are known for their unique features.

2. **Analyzing the Options**:
- **Option 1: Habitat - Exclusively Marine**:
- Echinoderms are indeed exclusively marine organisms. They live in oceanic environments and cannot survive in freshwater. This option is applicable to Echinodermata.

- **Option 2: Symmetry - Adults are Radially Symmetrical**:
- Adult echinoderms exhibit radial symmetry. For example, a starfish can be divided into equal parts along multiple planes. This is also applicable to Echinodermata.

- **Option 3: Body System - Presence of Canal System**:
- Echinoderms do not possess a traditional canal system. Instead, they have a unique water vascular system that is crucial for their movement and feeding. This option is misleading because it incorrectly refers to a "canal system" instead of the correct term "water vascular system." Therefore, this option is not applicable to Echinodermata.

- **Option 4: Indirect Development**:
- Echinoderms typically undergo indirect development, meaning they have a larval stage before becoming adults. This option is applicable to Echinodermata.

3. **Conclusion**:
- The option that is not applicable to members of the phylum Echinodermata is **the presence of a canal system**. Instead, they have a water vascular system.

### Final Answer:
The correct answer is: **Presence of canal system due to the folding of body wall**.

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