Which is the most distinct character of fishes?

Options

A. Gills
B. Scales
C. Lateral line organ
D. Paired fins and fin rays

Answer

**Step-by-Step Solution:**

1. **Identify the Characteristics of Fishes**: To determine the most distinct character of fishes, we need to look at various features that are commonly associated with them.

2. **Examine Gills**: Fishes typically have gills for respiration. However, it's important to note that some amphibians and reptiles also possess gills at certain life stages, making this feature not unique to fishes.

3. **Consider Scales**: Fishes have scales covering their bodies. Yet, scales are also found in reptiles, which means this characteristic is not exclusive to fishes.

4. **Look at the Lateral Line Organ**: This organ helps fishes detect movement and pressure changes in the water. However, it is also present in some amphibians, indicating that it is not a unique feature of fishes.

5. **Evaluate Paired Fins and Fin Rays**: Fishes possess paired fins and fin rays, which are crucial for their movement in water. This feature is distinct to fishes and is not found in any other class of animals.

6. **Conclusion**: Based on the analysis of these characteristics, the most distinct character of fishes is the presence of paired fins and fin rays.

**Final Answer**: The most distinct character of fishes is the presence of paired fins and fin rays.

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