Sacculina carcini parsitizes crabs, mostly the green crab Carcinus maenas (1). It is most commonly found in Europe, but has also been reported in North America (1). It is best known for the morphological transformations it induces in male crab hosts, which make the crabs take on more female characteristics, while females remain unchanged (2).
Female free-living larvae of the parasite swim through the water until they find a suitable crab host. They then inject infective cells into the crab, which develop into an internal root system throughout the host body (the interna). Nutrients are absorbed from the host. When ready, the parasite develops a reproductive apparatus that penetrates through the crab to the exterior (the externa). Free-swimming male larvae can then mate with the female externa. Larvae are then released back into the water (3).
1. 10.1016/j.jip.2020.107338
2. 10.1007/s00227-012-1988-4
3. 10.1093/jcbiol/ruy044
Parasite Comics Team:
Dr. Chenhua Li (Lead, Ideas), Dr. Þórey Jónsdóttir (Illustrator, Ideas), Stephen Pollo (Writer, Researcher), Yuanzhe Wang (Digital Consultant).