Definition of glochidium in US English:

glochidium

noun

Zoology
  • A parasitic larva of certain freshwater bivalve mollusks, which attaches itself by hooks and suckers to the fins or gills of fish.

    • ‘Unionid embryos spend the first stage of development in the marsupial portion of the female unionid's gills, where they develop into glochidia, the parasitic stage.’
    • ‘Many mussel species depend on specific species of fish to serve as hosts for mussel larvae, or glochidia.’
    • ‘The glochidia larvae of some freshwater mussels can be serious parasites of fish, and some marine bivalves bore through wood, causing damage to wooden ships, pilings, and other wood structures.’
    • ‘Zygotes develop within the mantle cavity and glochidia larvae are released in the early summer.’

Origin

Late 19th century: modern Latin, based on Greek glōkhis, glōkhid- ‘arrowhead’.

Pronunciation

glochidium

/ɡlōˈkidēəm/