What is the meaning of "ectothermal animal"?

Explanation

### Step-by-Step Solution:

1. **Definition of Ectothermal Animals**:
- Ectothermal animals are those whose body temperature is not constant and varies with the temperature of their surrounding environment.

2. **Characteristics**:
- The body temperature of ectothermal animals fluctuates according to external conditions. This means that when the environment gets warmer, their body temperature increases, and when it gets cooler, their body temperature decreases.

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