| Popis: |
Six new species of the genus Onyx are described from different coastal zones in Vietnam based on samples collected between 2004 and 2010. Onyx cangionensis sp. n. is characterised by the fact that males have 14-16 equal-sized and equal-distantly arranged sigmoidal precloacal tubular shaped supplements. Onyx blomei sp. n. is characterised by sexual dimorphism in the shape of the amphidial fovea. The male has an atypical amphid with posterior part spiral shaped with 2.5 turns and anterior part hook shaped, whereas the amphidial fovea in the female is simply multispiral with 2.25 turns. Onyx orientalis sp. n. is characterised by its very long cephalic setae and the presence of 18 light-refractive, slightly S-shaped, precloacal tubular supplements in the males. Onyx cobbi sp. n. is also characterised by its sexual dimorphism in the shape of the amphidial fovea: an elongated loop in the male and a multispiral in the female. There are 15 slightly S-shaped, precloacal supplements. The anterior supplement is half the size of the others. Onyx paradimorphus sp. n. is characterised by a multispiral amphidial fovea, spicules regularly bent, strongly cuticularised, 15 S-shaped supplements and 5 papillae with setae within the spicules region. Onyx mangrovi sp. n. is characterised by 17-23 supplements with a complex structure: anterior part is sigmoidal-shaped, posterior part is hook-shaped and by its very short tail with dorsally curved tip. |
