Cyclostomate have ............... fins at the back a tail fin that helps in swimming.

Answer

**Step-by-Step Solution:**

1. **Understanding Cyclostomata**: Cyclostomata are a group of primitive vertebrates that include species such as lampreys and hagfish. They are characterized by their lack of jaws and paired fins.

2. **Characteristics of Cyclostomata**: These organisms are typically elongated and have a round body shape. They are also known for being parasitic, feeding on other fish during their adult stage.

3. **Fins in Cyclostomata**: Cyclostomata do not possess paired fins or appendages. Instead, they have a unique fin structure.

4. **Back Fins**: Cyclostomata have two fins located at the back of their body. These fins play a crucial role in locomotion, helping them swim effectively.

5. **Conclusion**: Therefore, the answer to the question is that Cyclostomata have **two fins** at the back, along with a tail fin that aids in swimming.

**Final Answer**: Cyclostomata have **two** fins at the back.

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