Glochidium: specialist larval form in some freshwater bivalves, characterized by a bivalve shell, with or with a pair of hooks, and a long adhesive thread or tentacle. It lives as a temporary parasite on the gills or fins of fish. In some species a modified glochidium is termed a 'lasidium' before attachment and a 'haustorium' after attachment (Stachowitsch, 1992).
- Stachowitsch, M., 1992. The invertebrates: an illustrated glossary. Chichester: John Wiley & Sons, Inc.
Definition specific to species of freshwater mussels of the families Unionidae and Margaritiferidae.