Name a colourless dinoflagellate.

Explanation

**Step-by-Step Solution:**

1. **Identify the Organism**: The question asks for a colorless dinoflagellate. Dinoflagellates are a group of single-celled organisms that are often found in marine environments.

2. **Name the Colorless Dinoflagellate**: The specific colorless dinoflagellate that is commonly recognized is called **Noctiluca**.

3. **Understand its Characteristics**: Noctiluca is known for its lack of chloroplasts, which is why it is colorless. Unlike many other dinoflagellates that are photosynthetic, Noctiluca does not produce its own food through photosynthesis.

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