File:Tail of microfilaria in microscopy.jpg

English: The tail of a microfilaria, when viewed under a microscope, is an important morphological feature that can be used for species identification. The shape and characteristics of the tail can vary among different species of microfilariae. Here are some common types of tails seen in microfilariae: Sheathed Microfilaria- Some microfilariae have a sheath that covers part or all of their body, including the tail. This sheath can be an important diagnostic feature. For example, Onchocerca volvulus, which causes river blindness, has a sheathed microfilaria with a long, tapering, and pointed tail that extends beyond the sheath. The tail is often coiled or curved. Unsheathed Microfilaria-Microfilariae of some species lack a sheath and have exposed tails. The shape and size of the tail can still vary between species. For instance, the microfilaria of Wuchereria bancrofti, which causes lymphatic filariasis, has a relatively short, blunt, and rounded tail. Caudal Nucleus- Another important feature to look for when examining the tail of a microfilaria is the presence or absence of a caudal nucleus, which is a distinct, rounded, or elongated structure located in the posterior part of the worm. The presence or absence of a caudal nucleus can be used for species identification. Tail Morphology- The tail may also have unique morphological characteristics such as knobs, spines, or other structures that can be used for distinguishing between species.