noun. The parasitic larva of most freshwater mussels, having hooks for attaching to the gills or other external parts of a host fish.

noun. [capitalized] In zoology, a generic name given to the young of certain fresh-water mussels, as Unio and Anodonta, which are hatched in the gills of the parent, and were at one time supposed to be parasites. Rathke

noun. In botany, a hair-like appendage to the massulæ of heterosporous Filicineæ, by which the massulæ attach themselves to the macrospores after both have been discharged into the water.

noun. The larva or young of the mussel, formerly thought to be a parasite upon the parent's gills.

noun. The larva or young of the mussel.

noun. a barbed spine or bristle (often tufted on cacti)

"A fish is infinitely more mobile than a mussel; it can swim a long way in the one-to-three-month period during which a glochidium is on its gills."

pricker  prickle  spikelet  spine  sticker  

glochidcia  glochidia