Heth impalutiensis n. sp. (Nematoda: Ransomnematoidea: Hethidae) a millipede parasite from Central Mindanao, Philippines

Abstract

The nematode Heth impalutiensis n. sp. is described from an unidentified spirostreptid millipede (Harpagophoridae) from the Bukidnon Province of Mindanao, the Philippines. Based on morphological characters, H. impalutiensis n. sp. is closest to Asian-Pacific representatives of the genus. Females of H. impalutiensis n. sp. are close to H. dimorphum and H. vietnamensis in body size and form of the lateral lappets, but can be distinguished by the significantly longer tail. Males of H. impalutiensis n. sp. strongly resemble that of H. xaniophora by the presence of such a rare character combinations as mammiform papillae and a bursa-like cuticular fold, but can be easily differentiated by the numbers of genital papillae (7 vs 6 pairs, respectively). Heth impalutiensis n. sp. can be distinguished from all nominal species by hypertrophy of the anterior anal lip in females which overlaps the anal aperture. Phylogenetic analysis based on the newly obtained set of sequences did not provide an evidence of infraorder Rhigonematomorpha monophyly as two superfamilies Ransomnematoidea and Rhigonematoidea formed independent clades in the frames of ascaridid-spirurid-oxyurid super clade (Clade III of Nadler et al., 2007).

Molecular identification of a new species of Rhigonema (Nematoda: Rhigonematidae) and phylogenetic relationships within the infraorder Rhigonematomorpha

“…The phylogenetic results of the present study are largely congruent with the traditional classifications of the Rhigonematomorpha [1,2,4], which support the division of this taxon into two superfamily Rhigonematoidea and Ransomnematoidea. Our results are also in agreement with those of a previous molecular phylogenetic study based on 18S + 28S sequence data [3], but conflict with some molecular phylogenies using single 18S or 28S sequence data [5][6][7]19].…”

“…Although some previous molecular phylogenetic studies made some attempts to solve the evolutionary relationships of Rhigonematomorpha and its related taxa (i.e. Ascaridomorpha, Spiruromorpha and Oxyuridomorpha), as well as the systematic status of some families or genera in the Rhigonematomorpha [3,5,6,15,16,[22][23][24]65], the basic molecular phylogenetic framework for the Rhigonematomorpha is far from complete. The phylogenetic results of the present study are largely congruent with the traditional classifications of the Rhigonematomorpha [1,2,4], which support the division of this taxon into two superfamily Rhigonematoidea and Ransomnematoidea.…”

“…According to the current classifications, which are mainly based on morphological characters, Rhigonematomorpha is divided into six families assigned into two superfamilies, namely Rhigonematoidea (Rhigonematidae, Ichthyocephalidae, Xustromatidae) and Ransomnematoidea (Carnoyidae, Hethidae, Ransomnematidae) [1,2,4]. However, the monophyly and phylogenetic relationships of these six families are still under debate [3,[5][6][7].…”

“…Several recent studies have provided some nuclear and mitochondrial (mt) DNA sequence data [i.e. the small subunit ribosomal DNA (18S), the large subunit ribosomal DNA (28S) and the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene or the mitochondrial genome] that can be used for species identification or phylogeny of Rhigonematomorpha [6,[14][15][16][17][18][19]. However, the current genetic database for these nematodes remains very limited.…”

A novel copro-diagnostic molecular method for qualitative detection and identification of parasitic nematodes in amphibians and reptiles

“…This genus lies phylogenetically within the Cosmocercidae, including species known to infect amphibians [ 36 , 37 ]. The next highest matches were from Rhigonema ingens and species of the genus Heth which are parasites of arthropods [ 38 , 39 ]. The fifth match was from the nematode parasite Pseudonymus islamabadi documented from the lizard, Iguana iguana [ 40 ].…”