Surface ultrastructure of larval Gnathostoma cf. binucleatum from Mexico

We examined the morphology of gnathostome larvae obtained in Temazcal and S inaloa, Mexico, mainly using scanning electron microscopy. The mean body le ngth was 4.67 mm. The head had 4 transverse rows of hooklets, and the mean number of each row was 40, 44, 47, and 50. The bodies were wholly covered w ith minute cuticular spines along their transverse striations. The mean num ber of striations varied from 227 to 275. The cervical papillae were situat ed between the 13th and 17th transverse striations, and most specimens had them between the 14th and 15th transverse striations. An excretory pore was also located between the 24th and 28th transverse striations. We identifie d this Mexican gnathostome as Gnathostome cf. binucleatum Almeyda-Artigas, 1991.