For parasitoids, see Parasitoid.
This is an incomplete list of organisms that are true parasites upon other organisms.
Endoparasites
(endo = within; parasites that live inside their hosts)
Plants
Parasitic worms
These can be categorized into three groups; cestodes, nematodes and trematodes. Examples include:
- Acanthocephala
- Ascariasis (roundworms)
- Cestoda (tapeworms) including: Taenia saginata (human beef tapeworm), Taenia solium (human pork tapeworm), Diphyllobothrium latum (fish tapeworm) and Echinococcosis (hydatid tapeworm)
- Clonorchis sinensis (the Chinese liver fluke)
- Dracunculus medinensis (Guinea worm)
- Enterobius vermicularis (pinworm)
- Filariasis
- Hookworm
- Loa loa
- Onchocerciasis (river blindness)
- Schistosomiasis
- Strongyloides stercoralis
- Tapeworm
- Toxocara canis (dog roundworm)
- Trichinella
- Whipworm
Protozoans
- Entamoeba histolytica and Entamoeba coli - can cause Amoebiasis
- Acanthamoeba
- Balamuthia mandrillaris
- Giardia
- Cyclospora cayetanensis
- Cryptosporidium
- Toxoplasma gondii
- Leishmania - L. tropica, L. donovani, and L. mexicana are known to cause Leishmaniasis.
- Plasmodium - causes the fatal disease, Malaria. P. falciparum, P. vivax, and P. malariae are pathogenic to humans.
- Babesia
Fungi
- Gymnosporangium and other rusts
- Pyrenophora teres
- Cordyceps
Arthropods
Ectoparasites
(ecto = outside; parasites that live on but not within their hosts, for example, attached to their skin)
Arthropoda
- Acari
- Cymothoa exigua
- Amblyoponinae (Dracula ants)
- Bed bugs
- Culicidae (mosquitoes)
- Calyptra (moth) (vampire moths)
- Hippoboscoidea
- Tsetse fly
- Lipoptena
- Melophagus ovinus, (sheep keds) and relatives
- Oestridae (bot flies)
- Human botfly
- Cuterebra fontinella (mouse botfly)
- Phlebotominae (sand flies)
- Phthiraptera (Lice)
- Siphonaptera (fleas)
- Tabanidae (horse flies)
- Tantulocarida
- Triatominae
- Pea crab
- Sacculina
Annelids
Monogeneans
Monogeneans are flatworms, generally ectoparasites on fish.
Mollusks
Chordates
- Cookiecutter shark
- Candiru (vampire fish of Brazil, a facultative parasite)
- Lampreys
- Male Deep sea anglers
- False cleanerfish
- Hood mockingbird
- Oxpeckers (cleaning symbiosis)
- Snubnosed eel
- Vampire bat
- Vampire finch
- Cuckoo (brood parasite)
- Cowbird (brood parasite)
Plants
- Mistletoe
- Monotropa uniflora
- Certain orchids
- Nuytsia
- Orobanche (broomrape)
- Santalum album
- Certain plants with albinism
Fungi
- Corn smut
- Certain mushrooms
- Asterotremella albida