1. Body size: Tilapia are larger, up to 60 centimeters or more in length, with a spindle-shaped body. The guppy (Mandarin fish, seasonal flower fish) is smaller, about 15 centimeters long, with an oval-shaped body.

2. Head: The head of tilapia is longer, while the head of guppy (Siniperca chuatsi, Chihuahua) is shorter.

3. Mouth: Tilapia has a larger mouth, while guppies (Mandarin fish, seasonal flower fish) have a smaller mouth.

4. Eyes: The eyes of tilapia are small, while the eyes of guppies (Mandarin fish, seasonal flower fish) are large and prominent.

5. Markings: The markings on tilapia are striped, while the spots on guppies (mandarin fish, monsoon fish) are round.

6. Dorsal fin: Tilapia has two segments of dorsal fin while guppy has only one.

7. Scales: Tilapia has large scales, while guppies (Mandarin, Seasonal Fish) have fine scales.

8. Adaptability to water temperature: Tilapia is suitable for growing in a cooler water temperature, which is usually around 20℃. While guppies (Mandarin fish, seasonal fish) are suitable to grow in a higher water temperature environment, the water temperature is usually above 25℃.

To summarize, tilapia and guppy (Siniperca chuatsi, Seasonal Flowering Fish) are distinctly different in body size, head, mouth, eyes, markings, dorsal fins, scales, and water temperature adaptability.