The normal life span of river crabs is two years. The river crabs bought on the market are sexually mature river crabs, which can normally live for 1 month, and if the water temperature is about 5 degrees Celsius, they can live for about 6 months in hibernation. Your river crab is not recommended for breeding, it can live for two weeks at most, and it will hurt your feelings when it dies. Generally, you should feed small loach fish to the pet-level river crabs. If you raise river crabs to play, it is recommended that a dollar-sized river crab is best.