Name an organism found as secondary carnivore in an aquatic ecosystem.

Explanation

**Step-by-Step Solution:**

1. **Understand the Concept of Carnivores**: Carnivores are organisms that primarily consume other animals. In an ecosystem, they can be classified into different levels based on their position in the food chain.

2. **Identify the Levels in the Food Chain**:
- **Producers**: In an aquatic ecosystem, the primary producers are phytoplankton, which are microscopic plants that float in the water.
- **Primary Consumers**: These are organisms that eat the producers. In this case, zooplankton feed on phytoplankton.
- **Secondary Consumers**: These are organisms that eat the primary consumers. Small fish can be considered as secondary consumers because they eat zooplankton.
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