Parapharyngodon pereiramendoi De Sousa-Silva 2024

Parapharyngodon pereiramendoi De Sousa-Silva sp. n. (Figures 1 (a–h), 2 (a–f), and 3(a–e)) Taxonomic summary Type host. Corythomantis greeningi (Hylidae: Lophyohylinae) Type locality. Ecological Station of Aiuaba, Aiuaba municipality, Ceará State, Northeastern Brazil (6.000°S, 39.999°W). Site of infection. Large intestine Numbers of parasite specimens/hosts. (309/11) Prevalence. 100% Mean intensity of infection. 28.1 ± 13.41 Range. 1–78 Other localities. Barro municipality (7°10'36''S, 38°46'54''W), Ceará state (Host: C. greeningi). Etymology. The species is named after the indigenist Bruno Pereira and the conservationist Chico Mendes for their work in protection, preservation, and conservation of the Amazon Forest and the Indigenous peoples in Brazil. Description General. Robust and fusiform nematode, pale white (whitish), cuticle with well-defined transverse striations from the anterior portion of the body to the base of the caudal filament. Evident sexual dimorphism, with males approximately half the size of females. Lateral alae are absent in both sexes. Male with triangular mouth opening, having four bilobed lips, one dorsal, two ventrolateral, and one ventral (Figures 1 (b) and 3(a)). A pair of amphids located on the ventrolateral lips, close to the oral opening (Figures 1 (b) and 3(a)). Nerve ring located in the first anterior third of the pharynx region (Figures 1 (a, c)). Oesophagus with characteristics of Oxyuridae (Adamson 1989), bulb with developed muscular valve projected through the first portion of the intestine. The opening of the excretory pore is post-bulbar and has a vesicular body surrounding the excretory duct. Spicule small and slightly sclerotised (Figures 1 (f) and 2(c)). Gubernaculum absent. Cloacal region with a short V-shaped support (Figures 2 (e) and 3(b, e)). Three pairs of mammiliform caudal papillae (one pair near the upper cloacal lip, one pair ad-cloacal, and the third pair fused, located at the base of the caudal filament in males) (Figures 1 (e), 2(e), and 3(b, e)). The caudal alae are absent. Female with triangular oral opening with three bilobed lips (Figures 1 (d) and 3(c)), amphids opening in ventrolateral lips. The opening of the excretory pore is post-bulbar and has a vesicular body surrounding the excretory duct (Figures 1 (c) and 2(b)). Vulva in equatorial position and conical tail (Figures 1 (c, g), 2(b) and 3(d)).Eggs with a subterminal operculum, thick external coating, and not embryonated (Figures 1 (h), 2(d)). Male. (Based on the holotype and 16 paratypes). Total body length 2.10 ± 3.2 (1.36–2.65) mm (Figures 1 (a) and 2(a)). Body width at oesophagus-intestine junction 166.7 ± 23 (130–219). Nerve ring and excretory pore located at 134 ± 8 (115–148) and 596.7 ± 62 (514–703) from anterior end, respectively. Oesophagus total length 405 ± 22 (370–448), representing 19% of total body length; corpus length 294 ± 18 (264–328), corpus width 34.1 ± 4 (24–40), isthmus length 21.4 ± 4 (14–31), isthmus width 24.8 ± 3 (19–30), bulb length 90 ± 9 (70–104), bulb width 96.6 ± 11 (75–120) (Figures 1 (c) and 2(f)). Testicle extending anteriorly from mid-body region (Figure 1 (c)). Vas deferens not observed. Spicule poorly sclerotised, sharply pointed 51.6 ± 5 (43–62) (Figures 1 (f) and 2(c)). Anterior anal lip echinate, with smooth, short projections: irregular, not well developed, small finger-like outgrowths (Figure 3 (e)). Genital cone with short projection, present at the base of the posterior anal lip (Figure 3 (e)). Three pairs of mammilliform caudal papillae distributed as follows: one pair just above the anterior cloacal lip, the second pair sublaterally ad-cloacal, and the third pair sharing a fused base near the base of the caudal filament (Figures 1 (e), 2(e), and 3(b, e)). Long tail inserted dorsally 100.9 ± 7 (90–115) (Figures 1 (a, e), and 3(b)). Female. (Based i=on one allotype and 20 paratypes). Total body length 3.13 ± 6.1 (2.32–4.02) mm (Figures 1 (c) and 2(b)). Body width at oesophagus-intestine junction 325.2 ± 58 (196–401). Nerve ring and excretory pore located at 136.9 ± 10 (116–158) and 843.7 ± 144 (666–1099) from anterior end, respectively. Oesophagus total length 602.9 ± 28 (545–643), representing 19% of total body length; corpus length 451.6 ± 20 (406–481), corpus width 46.8 ± 3 (41–51), isthmus length 26.5 ± 6 (14–39), isthmus width 36.8 ± 3 (32–45), bulb length 124.3 ± 9 (101–139), bulb width 133.7 ± 8 (120–158) (Figures 1 (c) and 2(b)). Vulva with prominent lips situated at mid-region of the body, 1566.4 ± 294 (1196–2000) from anterior end (Figures 1 (c) and 2(b)). Monodelphic, prodelphic, and post-bulbar ovary. Eggs thickshelled, non-embryonated, with subterminal single operculum, 116.6 ± 2 (73–135) × 51.4 ± 1 (35–66) (Figures 1 (g) and 2(d)) and not embryonated. Tail conical, pointed, 314.2 ± 49 (229–387) (Figures 1 (h), 2(b) and 3(d)). Remarks Among the Parapharyngodon species that occur in the Neotropical realm the males of P. alvarengai, P. bainae, P. hispidus, P. largitor, P. riojensis, P. sanjuanensis, P. sceleratus, P. silvoi and P. verrucosus differ from males of P. pereiramendoi sp. n. by the absence of a genital cone, while in the new species it is present (Table 1), and the males of P. curupira, P. hugoi, and P. politoedi differ from males of P. pereiramendoi sp. n. by the presence of a lateral ala, while in the new species it is absent (Table 1). Regarding the females, P. alvarengai, P. bainae, P. curupira, P. hispidus, P. largitor, P. sceleratus and P. verrucosus differ from females of P. pereiramendoi sp. n. by having an ovary in a pre-bulbar position, while the new species has the ovary in a post-bulbar position (Table 2); P. hugoi, P. largitor, P. politoedi and P. riojensis differ from females of P. pereiramendoi sp. n. by having the vulva pre-equatorial or post-equatorial, while a new species have the vulva equatorial (Table 2); P. sanjuanensis and P. silvoi differ from females of P. pereiramendoi sp. n. by having a stout spike in the caudal end, while the new species has a conical and pointed cauda (Table 2). In addition to P. pereiramendoi sp. n., five other species have been described infecting hylid hosts: P. chamelensis (Nearctic realm, Bursey and Goldberg 2015; Velarde-Aguilar et al. 2015), P. curupira (Neotropical realm, Santos AN et al. 2022), P. hylidae and P. osteopili (Panamanian realm, Bursey and Goldberg 2015; Velarde-Aguilar et al. 2015), and P. politoedi (Neotropical realm, Santos T et al. 2018). Parapharyngodon pereiramendoi sp. n. differs from P. chamelensis by the absence of a single papilla on the ventral lip of the oral region, lateral lobes of the genital cone V-shaped, and a single postanal papilla with two nerve endings located on the medium lobe of the posterior lip. It differs from P. hylidae by having a mouth with four lips and a non-pedunculated amphid. It differs from P. politoedi by the absence of a lateral ala and by having four bilobed lips. It differs from P. osteopili by the absence of the four large submedian papillae and an oral ring internal to the buccal cavity with six small papillae. Parapharyngodon pereiramendoi sp. n. differs from P. curupira by the presence of four bilobed lips and the absence of cephalic papillae and lateral alae.