Which one is a true fish?

Options

A. Jellyfish
B. Starfish
C. Dogfish
D. Silverfish

Explanation

To determine which one is a true fish among the given options, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Options**: The options provided are jellyfish, starfish, dogfish, and silverfish.

2. **Analyze Each Option**:
- **Jellyfish**:
- Shape: Cylindrical vase-shaped.
- Classification: Belongs to the phylum Cnidaria.
- Characteristics: Free-swimming marine animals with a gelatinous umbrella-shaped bell and tentacles for capturing prey.
- Conclusion: Not a true fish.

- **Starfish**:
- Shape: Star-shaped.
- Classification: Belongs to the phylum Echinodermata.
- Characteristics: Marine invertebrates with a central disc and five arms.
- Conclusion: Not a true fish.

- **Dogfish**:
- Classification: Belongs to the class Chondrichthyes, which is under the phylum Pisces.
- Characteristics: Known for their ability to smell, they are true fish.
- Conclusion: This is a true fish.

- **Silverfish**:
- Classification: A wingless insect that belongs to the phylum Arthropoda.
- Conclusion: Not a true fish.

3. **Determine the Correct Answer**:
- Among the options analyzed, the only one that qualifies as a true fish is the **dogfish** (Scoliodon).

### Final Answer:
The true fish among the options is **Dogfish**.

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