Which is not a member of echinodermata ?

Options

A. Star Fish
B. Ascaris
C. Sea Lily
D. Ophiuthrix .

Answer

To determine which organism is not a member of the phylum Echinodermata, we will analyze each option provided in the question.

### Step 1: Identify the options
The options given are:
1. Starfish
2. Ascaris
3. Sea lily
4. Ophiothryx

### Step 2: Analyze each option
- **Starfish**: Starfish, also known as sea stars, are indeed members of the phylum Echinodermata. They belong to the class Asteroidea.

- **Ascaris**: Ascaris is a genus of parasitic roundworms. They belong to the phylum Nematoda, which is distinct from Echinodermata. Therefore, Ascaris is not a member of Echinodermata.

- **Sea lily**: Sea lilies are marine animals that belong to the class Crinoidea, which is part of the phylum Echinodermata. Thus, sea lilies are members of Echinodermata.

- **Ophiothryx**: Ophiothryx is a genus of brittle stars, which are also members of the phylum Echinodermata and belong to the class Ophiuroidea.

### Step 3: Conclusion
After analyzing each option, we find that the organism that is not a member of Echinodermata is **Ascaris**.

### Final Answer
**Ascaris** is not a member of Echinodermata.

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