Which of the following animals is not a pair of poikilotherms?

Options

A. Torpedo, Trygon
B. Trygon, panthera
C. Pristis, carcharodon
D. Scoliodon, Trygon

Answer

To solve the question about which of the following animals is not a pair of poikilotherms, we need to understand the definitions of poikilotherms and homeotherms.

### Step-by-Step Solution:

1. **Define Poikilotherms**: Poikilotherms are organisms whose internal body temperature varies with the temperature of their environment. Examples include most fish, amphibians, and reptiles.

2. **Define Homeotherms**: Homeotherms are organisms that can maintain a stable internal body temperature regardless of external environmental conditions. This includes birds and mammals, including humans.

3. **Analyze the Options**:
- **Option 1: Torpedo and Trigon**: Both are types of fish. Since fish are generally poikilotherms, this pair is made up of poikilotherms.
- **Option 2: Trigon and Panthera**: Trigon is a fish (poikilotherm), while Panthera (which includes big cats like lions and tigers) is a mammal (homeotherm). This pair contains one poikilotherm and one homeotherm.
- **Option 3: Terris and Carcharodon**: Both are fish (Carcharodon refers to the great white shark). Thus, this pair is also made up of poikilotherms.
- **Option 4: Scoliodon and Tigon**: Both are fish, making this pair poikilotherms as well.

4. **Identify the Incorrect Pair**: The only option that includes a homeotherm (Panthera) along with a poikilotherm (Trigon) is Option 2. Therefore, this is the pair that does not consist entirely of poikilotherms.

5. **Conclusion**: The answer to the question is that the pair that is not made up of poikilotherms is **Trigon and Panthera**.