Microscopy

A

A: Clonorchis sinensis egg.  These are small operculated eggs.  Size is 27 to 35 µm by 11 to 20 µm.  The operculum, at the smaller end of the egg, is convex and rests on a visible "shoulder."  At the opposite (larger, abopercular) end, a small knob or hook-like protrusion is often visible (as is the case here).  The miracidium is visible inside the egg.