What do crabs eat?

River crabs are omnivorous crustaceans. Animal foods include fish, shrimp, snails, mussels, earthworms and aquatic insects. Plant food includes duckweed, filamentous algae, Sophora alopecuroides, Ceratophyllum japonicum, Potamogeton crispus, Potamogeton malayi, black algae, Eichhornia crassipes, Alternanthera philoxeroides and pumpkin. Concentrated feed includes bean cake, vegetable cake, wheat, rice and corn. But generally speaking, aquatic plants and other foods are easy to obtain, so in the natural environment, the food composition in the stomach is often dominated by plant foods.