mouth

Description:

Detail of the refringent organelle of Lieberkühn in Ophryoglena (also referred to as the "watchglass organelle" because of its shape). This is a unique feature of Ophryoglenid ciliates. It can be seen here as a small cup-shaped structure with a collection of pigmented refractile granules adjacent to its convex surface. This structure is thought to play a role in phototaxis which is positive in some phases of the life cycle and negative in others. From freshwater pond populated by dragonfly and mayfly nymphs near Boise, Idaho. Differential interference contrast.