glo·​chid·​i·​um | \ glō-ˈki-dē-əm How to pronounce glochidium (audio) \
plural glochidia\ glō-​ˈki-​dē-​ə How to pronounce glochidia (audio) \

Definition of glochidium

: the larva of a freshwater mussel (family Unionidae) that develops as an external parasite on fish

First Known Use of glochidium

1875, in the meaning defined above

History and Etymology for glochidium

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."

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The first known use of glochidium was in 1875

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Cite this Entry

“Glochidium.” Dictionary, Merriam-Webster, Accessed 25 Nov. 2020.

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