Different appearance and different growth environment.

1. The blood eel has a fat body, gray or brown body, dark or black spots on its back, and a long tail. The eel is yellow-brown in color, with a slender body and a bright yellow belly.

2. Blood eels grow in waters where fresh water and salt water meet, such as estuaries and shallow seas. Monopterus eels mainly grow in sandy areas in freshwater waters, ponds, rivers, etc.