1. Monopterus albus, an eel. Eel is one of about 15 species of slender eel-shaped fish in branchiae. There are two kinds of distribution in China, one is the common Monopterus albus, and the other is Monopterus albus, which is only distributed in Longchuan County, Yunnan Province. Monopterus albus sucks air directly through tiny blood vessels on the surface of throat, instead of breathing through gills like fish, because its gills are degenerated.

2. The serum of Monopterus albus is toxic, but the toxin is not heat-resistant and can be destroyed by gastric juice and heating. Generally, it will not be poisoned if it is cooked. Whether the treatment of eel blood for civilian use is caused by the toxin in the blood remains to be further studied. The blood of Monopterus albus is poisonous. Eating by mistake will stimulate the mucous membrane of oral cavity and digestive tract, seriously damage the nervous system, make people numb and die of respiratory and circulatory failure.

3. Monopterus albus has similar habits, genes and functions with Monopterus albus growing in mud and ponds. You can understand that in the process of biological evolution, some Monopterus albus can survive in water, while others go to make holes in the mountains.