glochidium
Concise Oxford English Dictionary © 2008 Oxford University Press:
glochidium /gləʊˈkɪdɪəm/
▶noun (pl. glochidia) Zoology a parasitic larva of certain freshwater bivalve molluscs, which attaches itself by hooks and suckers to the fins or gills of fish.
– origin C19: mod. L., based on Gk glōkhis ‘arrowhead’.
'glochidium' also found in these Oxford entries:

