External morphology of larvae of Chordodes morgani (Nematomorpha)

The surface features of larvae of a gordian worm, Chordodes morgani (Gordioidea), studied by scanning electron microscopy, were compared to those of other larval nematomorphs, until now known only from light microscopical studies. Larvae of C. morgani have a cylindrical body with 22 to 24 superficial segments, superficially divided at an ectodermal septum into a presoma and a trunk with a roughly 90 degrees bend. Papillae are located distally on the proboscis, the base of which is surrounded by circles of spines or scales. Although the major features of the larvae are similar to those known in other species, details visible with SEM hold promise for providing useful diagnostic characters.