The glochidium is a microscopic larval stage of some freshwater mussels, aquatic bivalve mollusks in the families Unionidae and Margaritiferidae, the river mussels and European freshwater pearl mussel
The swan mussel, Anodonta cygnea, is a large species of freshwater mussel, an aquatic bivalve mollusc in the family Unionidae, the river mussels.
Glochidium
…A drawing of the glochidium of the swan mussel (Anodonta cygnea). The larva is 0.35 mm long Glochidia of the mussel Lampsilis higginsii The glochidium (plural glochidia) is a microscopic larval stage…