- Protozoan parasites that infect the intestines
- Cryptosporidium hominis is the human subtype
- Cryptosporidium parvum is the bovine subtype, which can also occasionally infect humans
- Other species:
- C. meleagridis, mainly infects birds but can also infect humans
- C. cuniculus
- C. ubitquitum
- C. viatorum
- C. C. canis
- C. felis
- C. muris
