In which class of fishes mouth is located ventrally?

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the class of fishes that have their mouth located ventrally, which means the mouth is positioned on the underside of the body.

2. **Identifying Classes of Fishes**: There are three main classes of fishes:
- Osteichthyes (bony fishes)
- Chondrichthyes (cartilaginous fishes)
- Agnatha (jawless fishes)

3. **Analyzing Mouth Position**:
- In **Chondrichthyes**, which includes sharks and rays, the mouth is located on the ventral side (the underside) of the body.
- In **Osteichthyes**, the mouth is typically located at the anterior end (front) of the body.
- In **Agnatha**, such as lampreys and hagfish, the mouth is also located at the anterior end but does not have jaws.

4. **Conclusion**: Based on the analysis, the class of fishes that has a mouth located ventrally is **Chondrichthyes**.

5. **Additional Features**:
- Chondrichthyes are characterized by a skeleton made of cartilage instead of bone.
- They are also known as jawed fishes and possess placoid scales.
- They do not have an operculum, which is the bony covering over the gills found in bony fishes.

**Final Answer**: The class of fishes in which the mouth is located ventrally is **Chondrichthyes**.

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