Objective To observe the ultrastructural characteristics of adult Thelazia callipaeda in the Zunyi region.Methods T.callipaeda was collected from patients in the Zunyi area and nematode specimens were prepared.The ultrastructural characteristics of male and female worms were observed with a scanning electron microscope. Results Under a scanning electron microscope,the adult body was covered with a serrated cuticle with striations,and the body had 4grooves.The mouth opening was hexagonal,and there were 2semi...