The scientific name of these parasitic insects in crabs is crab slaves.

Crab slaves mainly live on the gills, abdomen and other parts of crabs and are contagious. The incidence begins in July, peaks in September, and decreases in October. Crab slaves grow by absorbing the nutrients of crabs, which will affect the growth of crabs and make the crab meat smell stinky, but it is harmless to the human body and can be killed by high-temperature cooking.