Two new skink-endoparasitic species of Meteterakis (Nematoda, Heterakidae, Meteterakinae) from East Asian islands

Abstract

Here, two new nematodes ofMeteterakisKarve, 1930 from Taiwan and the western Japanese Archipelago that are endoparasitic to scincid lizards are described. The TaiwaneseMeteterakisformosensissp. n.and the JapaneseMeteterakisoccidentalissp. n.can be distinguished from other congeners by the following characteristics: spicules 437–537 μm in length inM.formosensissp. n.and 359–538 μm inM.occidentalissp. n.; spicules with narrow alae, funnel-shaped, proximal ends ventrally bent; prevulval flap well-developed; gubernaculum mass absent; preclocal sucker with diameter of 35–47 μm inM.formosensissp. n.and of 32–36 μm inM.occidentalissp. n.; 9–15 caudal papillae on both lateral sides inM.formosensissp. n.and 10–14 inM.occidentalissp. n.; and relatively narrow lateral alae, ending at region near proximal end of spicule in male or at region anterior to anus in female.Meteterakisformosensissp. n.is distinguished fromM.occidentalissp. n.by possessing spicules with hyaline pointed distal ends and well-developed cuticular backing structures. The present study suggests that lateral alae can be used as diagnostic character among theMeteterakisspecies, and it revealed that meteterakine nematodes mature in the host’s small intestine and then migrate to the rectum to oviposit.