Parasitology Vocabulary

Symbiosis

2 different types of organisms living together

Mutualism

2 organisms of different species live in a relationship where both benefit

Commensalism

Relationship where 1 organism benefits & the other does not, but is not harmed

Parasitism

A relationship in which 1 organism lives off another (host) & causes harm to the host

Host

Any organism the supports another organism

Definitive Host

Kingdom Protista - the host in which the parasite undergoes sexual reproduction

Kingdom Animalia - the host in which the adult worm is found

Intermediate Host

Kingdom Protista - the host in which the parasite undergoes asexual reproduction

Kingdom Animalia - the host in which the juvenile form of the worm is found

Reservoir Host

infected organism (usually an animal) which makes the parasite available for transmission to other hosts

Ectoparasite

A parasite that lives on the outer surface of the host; ticks, lice, fleas

Endoparasite

A parasite that lives inside the host; tapeworm, Giardia, Plasmodium

Biological Vector

An organism in which the parasite undergoes part of its lifecycle & then transmits the parasite to another organism; female Anopheles mosquito

Mechanical Vector

An organism the transmits a parasite, but is not part of the parasites lifecycle; fleas, roaches, rodents

Hermaphrodite (monoecious)

Animal that has both male & female reproductive organs

Cyst

Spore like stage of protozoa; thick wall - resistant to unfavorable environment

Trophozoite

Active, motile, feeding stage of protozoa

Oocyst

Cyst form in genus Plasmodium, Cryptosporidium, & Toxoplasma

Nematodes

round worms, such as Ascaris, Enterobius, & hookworms

Filarial Worm

Thread-like roundworm

Microfilariae

Larval stage of thread-like roundworm

Larva

Juvenile form of a worm; larvae is plural

Ova

Egg

Platyhelminthes

Flat worms, such as trematodes (flukes) & cestodes (tapeworms)

Cysticeri

Larval stage of tapeworm, containing a single scolex within a thin walled bladder

Cercaria

Free swimming larval stage of trematodes (flukes)

Metacercaria

encysted stage of flukes