Dictionary of Tropical Medicine

Zebra fish

See Scorpaenidae.

Zooid

A specialised structure serving as an organ of a siphonophore such as Physalia. Different individuals in the colony often take on specialised functions such as feeding, defence and reproduction - up to a thousand zooids may be found in a single colony.

Zoonosis

An infection or an infectious disease transmissible under natural conditions from vertebrate animal and humans.

Zygote

The product of the union of a male and a female gamete.

Zymodeme

Subtypes of a microbial species that are separated on the basis of their isoenzyme patterns (eg. zymodemes of Entamoeba histolytica).