glo·​chid·​i·​um glō-ˈki-dē-əm How to pronounce glochidium (audio)
plural glochidia glō-ˈki-dē-ə How to pronounce glochidium (audio)
: the larva of a freshwater mussel (family Unionidae) that develops as an external parasite on fish

Word History


borrowed from New Latin, from Greek glōchid-, glōchī́s "projecting point (as the end of a yoke fastening or the barb of an arrow)" + New Latin -idium -idium; so named from the hook-like appendages with which the larvae attach themselves to fish — more at gloss entry 3

Note: Term introduced by the Norwegian zoologist Jens Rathke (1769-1855) in "Om Dam-Muslingen," Skrivter af Naturhistorie-Selskabet [Copenhagen], 4. Bind, 1. Hefte (1797), p. 166. As a vernacular equivalent of glochidium Rathke gives Krogskjæl, "hook shell."

First Known Use

1875, in the meaning defined above

Time Traveler
The first known use of glochidium was in 1875

Dictionary Entries Near glochidium

Cite this Entry

“Glochidium.” Dictionary, Merriam-Webster, Accessed 30 Mar. 2023.

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