What is a characteristic feature of Giardia lamblia?

Giardia lamblia is a flagellated protozoan known for its distinctive morphological features, particularly in its active trophozoite stage. A characteristic feature of Giardia lamblia is that it possesses two nuclei. This is important for identification under a microscope, as the organism's two nuclei contribute to its unique appearance, which distinguishes it from other protozoa. The presence of two nuclei is integral to its cellular organization and is a key feature utilized in laboratory identification during the diagnosis of giardiasis.

In contrast, while Giardia does form cysts for environmental survival, which is an important aspect of its lifecycle and transmission, the presence of two nuclei is a more defining and characteristic feature at the microscopic level.