what do barnacles do to crabs

Barnacles can infect crabs and manipulate their behavior to benefit themselves, all to the detriment of the unsuspecting crab. There are different types of barnacles that infect crabs, such as the rhizocephalan barnacle and the sacculinidae barnacle. The sacculinidae barnacle infects crabs and grows a root-like system throughout the crabs entire body, which the parasite uses to feed on the crab. As the parasite develops, part of its body grows outside of the crab on its lower abdomen, right where a crab would carry its eggs. The parasitic barnacle then manipulates the crab by tricking it into treating the parasite like it would treat its own eggs – carefully caring for and nurturing the parasite by protecting it, grooming it, and flushing it with oxygenated water. The rhizocephalan barnacle infiltrates and spreads within the body of its host and even alters its behavior and appearance. Infected crabs can be detected by the external reproductive structure of the rhizocephalan that grows where the crabs own eggs would be. The crab cleans and cares for this growth as if it were its own. Another type of barnacle infects king crabs and injects cells into the crabs bloodstream, causing the crab to become a good mother for the parasite egg sac. The male crabs even start to develop characteristics of a female crab, and their bodies are being taken over and used as factories by the parasite to make parasite larvae.