Crabs themselves eat very miscellaneous food, so it is not difficult to breed crabs, and there is no need to match them too low in diet. It is good to feed crabs by eating some small fish and shrimp.
Crabs are not picky eaters, so you can feed shrimps (crabs catch them by themselves or dried shrimps) in the water. Noodles, eggs, cabbage, dried beans, chicken, beef, etc. In short, crabs that people can eat are almost edible. It's better to be cooked, because raw will make the fish tank fishy.
Crabs are omnivorous animals, feeding on aquatic plants, benthos, organic debris and animal carcasses. When feeding, catch it with your claws, and then send the food to your mouth. It likes snails, shrimps, mussels, small fish and pumpkins, cooked potatoes, rice dregs, bread dregs and so on. These are harmless to humans and crabs.
If you are wild, you mainly eat some floating animals and plants. If you keep them yourself, you can feed them some aquatic plants or dried fish and worms. Crabs like a sandy environment. Don't forget to put more sand.
Crabs are omnivores. Generally, humus food is the main food in artificial breeding, and some breeders will also feed some dried fish or aquatic plants. Wild crabs are stocked. In the natural environment where the law of the jungle prevails, they feed on the carcasses of fish and shrimp, aquatic plants, snail meat, etc. In the case of food shortage, they will also feed on the same kind.
If you keep them at home temporarily, you can feed some sesame seeds and broken eggs to crabs, so that they can gain weight in just a few days. Crabs are not picky eaters, so it is ok to keep one or two at home. Shrimp, eggs, Chinese cabbage, dried bean curd, etc., are all eaten by crabs. However, it is recommended that these things fed to crabs should be cooked, because raw ones will make the water for raising crabs smell fishy soon.