of or having growing scales with a hard glossy surface of many layers of enamel, as in many extinct and some living fishes
noun
a fish having such scales, as the sturgeons, gars, and paddlefishes
See ganoid in American Heritage Dictionary 4
(gănˈoidˌ)
adjective
Of, relating to, or characteristic of certain bony fishes, such as the sturgeon and the gar, that have armorlike scales consisting of bony plates covered with layers of dentine and enamel.