First, the scavenger.

The most amazing thing about it is that it never chooses what to eat. It not only eats algae, but even eats the eggs and fish droppings of other fish. If the living environment is particularly bad, it may also eat garbage.

Eating casually will not affect its health, but also purify the surrounding environment. That's why it got the name "scavenger". People who keep fish at home often put a scavenger in the fish tank, which will clean up the feces of other fish.

Second, catfish.

Catfish is also considered as "the dirtiest fish in the world". This kind of fish is extremely tenacious and can live even in sewage. Like scavengers, they are not picky eaters at all. Besides eating garbage, they even eat the carcasses of other fish, and there are a lot of pollutants in their bodies. If we eat this kind of fish regularly, it will definitely affect our health.

Third, tilapia.

This kind of fish is "dirty" because it has a very strong vitality and can survive tenaciously in polluted water. The most terrible thing is that there are a lot of parasites in this fish, and these parasites are very harmful to human body. Moreover, some tilapia live in heavily polluted areas and even accumulate a lot of heavy metal elements in their bodies. Therefore, it is best not to use this kind of fish as food.

The cleanest fish:

First, mandarin fish.

Siniperca chuatsi is a freshwater fish belonging to the genus Siniperca, which is also called mandarin fish, crucian carp and octopus, etc. It is widely distributed all over the country. It is well-known because of Zhang Zhihe's "egrets flying in front of the Cisse Mountain, peach blossoms and flowing mandarin fish fat". It likes to live in rivers, lakes, reservoirs and other lush and clean water bodies, and it is carnivorous and fierce.

Second, the horse mouth fish.

Taguchi is a common freshwater fish, which is also known as Tripterygium wilfordii, Peach Blossom Plate, Makou, etc. It belongs to small freshwater fish of Cyprinidae and Taguchi in biological classification. It is widely distributed in all parts of China except the northwest, especially in mountain streams in hilly areas. In recent years, wild Taguchi has become less and less common due to over-hunting and ecological environment destruction.

Third, the fish.

Tilapia is a freshwater fish belonging to Cyprinidae and Silurus, and its scientific name is Crouching Red Silurus, also known as Crouching Mouth, Short-tailed Silurus, Yellow Palm Skin, etc. It is widely distributed all over the country, and likes to live in lakes with lush aquatic plants. In rivers, it usually lives in slow flow, is carnivorous, preys fiercely and is gluttonous, mainly in small fish, crustaceans, aquatic insects and bottom.