Immature stages of Acutogordius taiwanensis sp. n. A–B Live A cyst-form and B worm-form larvae in water C Posterior view of a worm-form larva D Cysts in an infected snail; E Worm-form larva under SEMF Anterior view of a larva showing the hook arrangement G Egg strings H Close-up of the proboscis. DS, dorsal spines; Ho, hooklet; LS, lateral spines; Peo, pseudointestine exterior opening; PostS, postseptum; PreS, preseptum; Pro, proboscis; PS, proboscis sheath; PsI, pseudointestine gland. Scale bars 50 µm (A–B), 2 µm (C), 50 µm (D), 10 µm (E), 5 µm (F), 1 cm (G), and 2 µm (H).