Actively moving organisms in aquatic ecosystem are

Options

A. Benthos
B. Zooplankton
C. Phytoplankton
D. Nekton

Answer

To solve the question regarding actively moving organisms in aquatic ecosystems, we will analyze each option provided:

1. **Benthos**:
- Benthos are organisms that live on or in the bottom sediments of aquatic environments. They typically crawl or are stationary and do not swim actively.
- **Conclusion**: Benthos are not actively moving organisms. (Wrong answer)

2. **Zooplankton**:
- Zooplankton are small aquatic organisms that drift in the water column. While they can move to some extent, they are primarily carried by water currents and are not capable of sustained, active swimming. They are often considered to be more or less stationary in their life cycle.
- **Conclusion**: Zooplankton are not actively moving organisms. (Wrong answer)

3. **Phytoplankton**:
- Phytoplankton are microscopic plants that also drift in the water. They are photosynthetic and are typically fixed in one place, relying on water currents for movement. They do not swim actively.
- **Conclusion**: Phytoplankton are not actively moving organisms. (Wrong answer)

4. **Nekton**:
- Nekton refers to aquatic organisms that can swim freely and actively in the water column. They are not bound to any specific location and can move independently throughout their aquatic environment.
- **Conclusion**: Nekton are actively moving organisms. (Correct answer)

**Final Answer**: The actively moving organisms in aquatic ecosystems are **Nekton** (Option 4).