Gnathostoma miyazakii is a medium-sized nematode with a narrow body. It has ten complete and one or two incomplete transverse rows of hooks on the head end, surrounding one pair of protruding unilobed lips. There are two papillae (small bumps) on each lip, with one amphid (small sensory depression) between each pair of papillae. Cervical papillae occur at about one-quarter of the length of the body from the head. The whole body is covered in spines, varying in size and shape depending on sex and region of the body. Spines towards the head end are well defined, while spines towards the tail end are scale-like. Males are about 49 mm long and just over 0.8 mm wide. The spicules (male mating structures) are blunt and unequal, with the left spicule about three-quarters as long as the right. Females are about 39 mm long and just over 0.8 mm wide. The eggs have two polar caps and have many pits on the surface. The type host was the North American river otter (Lutra canadensis), and the type locality was Black trout lake, Township 30, Range 22, Ontario, Canada. It has been reported from Canada and the United States. The typical location of infection in the primary host is the fibrous tissue of the kidneys.[1]
