The red arrow in the attached photomicrograph points to the amoeba’s nucleus. Nuclei can be hard to identify, as they are often similary to contractile vacuoles or food vacuoles. A simple method for identifying nuclei is to look for a circular or near-circular body, the outermost layer being clear, and the innerost spherical layer being a bit darker and/or granular than its surrounding layer. To the left of the nucleus, for comparison, is a food vacuole.
