SEM of specimens of Neoechinorhynchus johnii from Eleutheronema tetradactylus, Johnius carouna, and Otolithes ruber in the Pacific Ocean off Vietnam. (1) The proboscis and neck of a male specimen. (2) Two anterior proboscis hooks of another specimen. Note the curvature at the base of the otherwise straight hook. (3) Middle and posterior hooks in the proboscis in Figure 1. Note the location of the posterior hook at the furrow separating the proboscis from the neck. (4) A gallium cut cross-section of a hook showing its vacuolated hollow core. (5) A gallium cut longitudinal section near the edge of an anterior hook showing the distinction between the thin cortical layer and the dense core. Note the prominent posteriorly directed root and the slightly manubriated anterior end. (6) Micropores at the mid trunk of a male specimen.