Some nematodes of the genus Rhabdias Stiles et Hassall, 1905 (Nematoda: Rhabdiasidae) parasitising amphibians in French Guiana

Abstract

Based on material collected from Rhinella cf. margaritifera (Laurenti) and Rhi. marina (Linnaeus) (Anura: Bufonidae) during a parasite survey of the herpetofauna of French Guiana, updated descriptions of Rhabdias androgyna Kloss, 1971 and R. fuelleborni Travassos, 1926 are presented. In addition to metrical data, which may overlap in closely related species, emphasis is placed on qualitative characters. Rhabdias androgyna is distinguished by the unique presence of an outer and inner cephalic cuticular inflation, a shoulder-like broadening of the body at the anterior end, a wide and shallow buccal capsule (average buccal ratio 0.36) with serrated lumen in apical view, a prominent anterior dilatation of the oesophagus, and the presence of an additional posterior dilatation anterior to the oesophageal bulb. Characters that may help to differentiate R. fuelleborni from closely related species parasitising the Rhi. marina species group are the presence of six relatively uniform lips, and the division of the buccal capsule into an anterior and posterior segment, with differently structured walls. Both the presence of R. androgyna and R. fuelleborni in French Guiana constitute new geographic records. A single specimen of Rhabdias sp. is described from Pristimantis chiastonotus (Lynch et Hoegmood) (Anura: Craugastoridae). This species differs from all its Neotropical congeners by the distinct globular swelling of its head, similar to that seen in only one Palaearctic and one Afrotropical Rhabdias species. A list of species of Rhabdias parasitising amphibians in the Netropical Realm is also provided.

Diversity in the genusRhabdias(Nematoda, Rhabdiasidae): Evidence for cryptic speciation

“…The family comprises more than 111 described species belonging to eight genera, which primarily inhabit the lungs, but also the oesophagus and mouth, of amphibians and reptiles worldwide (Kuzmin, ; Tkach, Kuzmin, & Snyder, ). Rhabdias Stiles and Hassal, 1905 comprises approximately 80 nominal species distributed in the tropical‐temperate regions of the world (Kuzmin, Preez, & Junker, ; Lhermitte‐Vallarino et al, ) from which 15 are valid species in the Neotropical realm: R . alabialis Kuzmin, Tkach, & Brooks, ; R .…”

“…stenocephala Kuzmin et al, ; and R . tobagoensis Moravec and Kaiser, 1995 (Kuzmin et al, ). Rhabdias truncata Schuurmans Stekhoven, 1952 and R .…”

A new species ofRhabdias(Nematoda: Rhabdiasidae), a lung parasite ofPseudopaludicola pocoto(Anura: Leptodactylidae) from north-eastern Brazil: description and phylogenetic analyses

“…androgyna by body length, as R. pocoto n. sp. is much smaller than R. androgyna (3.41–7.43 × 9.35–13.4 mm) (Kloss, 1971), smaller buccal capsule (11–17 × 11–17 μm in the new species vs. 19–27 × 7–9 μm wide in R. androgyna ) and the particular shape of the anterior end of the body, as according to Kloss (1971) and Kuzmin et al (2015), R. androgyna has a shoulder-like circular dilatation with an extended cuticular swelling arranged in two layers, while the new taxon has two lateral inflations of cuticle containing an amorphous gland-like structure around the sub-apical lateral pores.…”

“…Based on the oral structure arrangement, the new species resembles those from the group are characterized by having six lips (four submedian and two lateral lips): Rhabdias androgyna Kloss, 1971, Rhabdias breviensis, Rhabdias fuelleborni Travassos, 1926, Rhabdias galactonoti Kuzmin, Melo, Filho & Santos, 2016, R. glaurungi , Rhabdias manantlanensis Martínez-Salazar, 2008, and Rhabdias stenocephala Kuzmin, Melo, Filho & Santos, 2016 (Martínez-Salazar, 2008; Nascimento et al ., 2013; Kuzmin et al , 2015; Kuzmin et al , 2016; Willkens et al , 2019). We will also compare R. pocoto n. sp.…”

“…Rhabdias fuelleborni parasitic in bufonid hosts (Kuzmin et al ., 2015) is distinguished by being larger than R. pocoto n. sp. (10–12 mm), and despite the two species sharing a morphology of the internal surface of the anterior and posterior segments of the buccal capsule, R .…”