Parasites are everywhere. They come in all shapes and sizes and can do a lot of harm to the host. Some parasites would just cling to the host and take only what’s enough to survive. However, there are those which can actually turn their host into a zombie-like creature and do whatever they want to do.
The barnacle Sacculina is a parasitic specie that targets crabs as their host. They shed their hard shells and inject themselves into the crab’s body. Once inside, it becomes a puppet master. They have the ability to control the crab and prevent it from reproducing, digesting, regenerating, growing and even molting. Instead, this reprogrammed crab focuses all its energy and time to nourish its parasitic master and even caring for the offsprings of the Sacculina. The parasite does not only get a home, but food and a babysitter as well.
During its larva stage, female specimen of the Sacculina has a hard outer shell, like the other barnacle species. Once she finds a host, it moves around the crab’s body until it finds a joint where it can easily inject itself inside the crab and leaves its outer shell, making the Sacculina a unique form compared to other kinds of barnacle.
Once inside the crab, it then develops a complex root system which is made out of tendrils. These then extend to the host’s abdomen, controlling its intestine and other parts of the crab’s digestive system. It also stretches out to the crab’s cerebral ganglion and thoracic ganglion which is equivalent to the brain and nerve center. The Sacculina then has control over the crab.