Number of gills found in osteichthyes is

Options

A. Two pairs
B. Four pairs
C. Five pairs
D. 6-15 pairs

Answer

To determine the number of gills found in Osteichthyes (bony fishes), we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Classification**: Osteichthyes is the class that includes all bony fishes. This class is divided into two main groups: ray-finned fishes and lobe-finned fishes.

2. **Identify the Gills**: Bony fishes typically have a specific number of gills. In Osteichthyes, the gills are located behind and to the side of the mouth cavity.

3. **Count the Pairs of Gills**: Bony fishes have a total of 4 pairs of gills. This means they have 8 individual gills.

4. **Gills Structure**: The gills are covered by a bony structure known as the operculum, which protects the gills and aids in respiration.

5. **Confirm the Function**: The gills are responsible for the exchange of gases (oxygen and carbon dioxide) in water, which is crucial for the fish's survival.

6. **Final Answer**: Therefore, the number of gills found in Osteichthyes is **4 pairs**.

### Conclusion:
The correct answer to the question is **4 pairs** of gills.

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