Incorrect set is

Options

A. Torpedo - electric organs
B. Trygon - poison sting
C. Carcharodon - claspers on pelvic fins
D. Betta - no operculum

Answer

To determine the incorrect set from the given options, we will analyze each option step by step.

### Step-by-Step Solution:

1. **Torpedo Electric Organs**:
- The torpedo is a type of electric ray that possesses electric organs. These organs allow it to generate electric shocks for defense and hunting.
- **Conclusion**: This set is correct.

2. **Trigon Poison Stink**:
- The term "trigon" refers to a group of rays, which can indeed have venomous spines that can cause a painful sting. Thus, the description of "poison stink" fits well with the characteristics of this organism.
- **Conclusion**: This set is correct.

3. **Karkarodon Claspers on Pelvic Fins**:
- Karkarodon refers to the genus that includes great white sharks. In sharks, the pelvic fins are modified into claspers in males, which are used for reproduction.
- **Conclusion**: This set is correct.

4. **Beta No Operculum**:
- The beta, commonly known as the betta fish, is a bony fish (class Osteichthyes). Bony fishes typically possess an operculum, which is a bony flap covering the gills. Therefore, the statement that bettas have "no operculum" is incorrect.
- **Conclusion**: This set is incorrect.

### Final Answer:
The incorrect set is **Beta No Operculum**.

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