Catfish are indeed omnivores, and their main diet consists of aquatic insects, organic detritus, etc., but they also eat live animals such as animal feces, small fish, and rodents. But in the aquaculture industry, animal manure is a cheap, non-toxic natural fertilizer that is fine as long as it is handled formally. In other parts of the country, information has been found many times about catfish being fed with slop or animal carcasses and offal. Catfish themselves love to eat this kind of rot and spoilage, and most of the catfish raised in captivity are raised in this kind of environment.

Catfish are hardy and can survive in very dirty environments, such as stinky city gutters. Some people claim that catfish are dirty because of their entrails, and since they can survive in human feces, some fish farmers intentionally feed them with human or pig feces. Living in a harsh environment for a long time, the catfish's body tends to accumulate toxic substances, such as heavy metals, which can't be eliminated no matter how much high-temperature cooking it undergoes.

Feces, as an economic and environmentally friendly natural fertilizer, is widely used in aquaculture in addition to growing organic vegetables, providing a large amount of nutrients for the plankton in the water. Because manure contains a large number of parasites and pathogenic bacteria, it can not be directly poured into the pond to use, before use, it is necessary to do fermentation treatment to kill parasites and pathogenic bacteria, and decompose the large molecule proteins in the manure into small molecule proteins and nutrients that can be easily utilized. Fermented feces will not undergo secondary fermentation in the pond, and also avoids excessive consumption of dissolved oxygen in the water during the decomposition of organic matter, which leads to hypoxia gas in fish. Direct discharge of feces into the pond is a practice that does not pay for itself, and can easily lead to oxygen deprivation and illness, or even death, of fish. Rumor has it that the article in the picture has a lot of catfish mouth wide open, exposed to the surface of the water is the reason for the lack of oxygen in the fecal water, the need to swallow air to supplement oxygen, and is not in the eating of feces...

You can't generalize and dismiss the innocence of all catfish just because one exists in a bad situation. Even the best catfish has a limited fighting ability, you let it live in water contaminated with all kinds of pathogenic bacteria all the time (inside the shit and garbage according to the rumors), it will get sick, and once it gets sick, it will die easily, and the farmers aren't stupid, who raises fish in order to raise them to death~~ Although catfish also live by eating corrosive food, there are other ones that eat corrosive food... Eel, hairy crabs, crayfish and so on, we do not have to be particularly nervous, as long as the production process is safe, you can eat without fear.

However, catfish, as an omnivore, they also eat meat, and being higher up the food chain does make it easier to enrich some harmful substances, which is a problem for all large animals, and it's an inevitable consequence of the food chain. The good news is that, from the current data, the market catfish is mostly farmed fish, basically there is no heavy metals, pesticide residues and other toxic and harmful substances exceeding the standard, or can be safely eaten. However, the regulation of farmed fish can not be relaxed, in addition, should also strengthen the management of industrial sewage discharge.