Final answer:
The Loa loa microfilaria has nuclei that do not extend to the tip of the tail, leaving a clear space at the tail tip, visible on a stained blood smear and aiding in diagnosis of loiasis.
Step-by-step explanation:
The arrangement of nuclei in the tail of Loa loa microfilaria is characteristic and can be used as a diagnostic feature. The microfilariae of Loa loa are sheathed and possess nuclei that do not extend to the tip of the tail. When observing a stained blood smear under a microscope, such as Wright-Giemsa stain, you would notice that the nuclei arrangement leaves a clear space at the tail tip, which is not the case with some other species of microfilariae. This specific arrangement forms an identifiable pattern that aids in the differentiation and diagnosis of Loa loa infection, which is known to cause the disease loiasis.