Under a high magnification of 400X, this photomicrograph revealed some of the ultrastructural features displayed by a Clonorchis sinensis egg. C. sinensis is a trematode, or fluke, and is also known as the Chinese, or oriental liver fluke. C. sinensis eggs are small, ranging in size from 27-35µm, by 11-20µm. The eggs are oval shaped with a convex operculum that rests on visible shoulders, at the smaller end of the egg. At the opposite, larger, abopercular end, a small knob, or hook like protrusion is often visible. The miracidium is visible inside the egg.