Parapharyngodon silvoi, De Araujo Filho, João A., Brito, Samuel V., Almeida, Waltécio De O., Morais, Drausio H. & Ávila, Robson W., 2015

De Araujo Filho, João A., Brito, Samuel V., Almeida, Waltécio De O., Morais, Drausio H. & Ávila, Robson W., 2015, A new species of Parapharyngodon (Nematoda: Pharyngodonidae) infecting Dermatonotus muelleri (Anura: Microhylidae) from Caatinga, Northeastern Brazil, Zootaxa 4012 (2), pp. 386-390 : 387

Parapharyngodon silvoi n. sp.

( Figs. 1 )

Male ( Fig. 1 ) based in four adult specimens (URCA-P 386): Length 1.1± 0.8mm (1.0– 1.1 mm); width at midbody 219.2 ± 19.8 (205–233). Triangular oral opening surrounded by 3 lips, esophagus 130.43 ± 12.32 (116–140) long: bulb length 71.1 ± 3.16 (67.7–73.9); bulb width 73.4 ± 3.89 (69.8–77.5); nerve ring 76.1 ± 10.65 (63.8–83.3); excretory pore 150.8 ± 12.76 (138.3–150.4) from anterior end. Tail 76.2 ± 6.72 (71.4–80.9) long; spicules equal, 63.3 ± 7.10 (56.6–70.8) long. Lateral alae 690.4 ± 251.8, beginning at 620.9 ± 186.17 from anterior end and ending at 55.7 ± 17.24 from posterior end; anterior cloacal lip smooth; caudal alae absent; caudal papillae in four pairs plus one unpaired papilla: 1 median precloacal pair, 1 sublateral pair in cloacal opening line, 1 median postcloacal pair, 1 pair in proximal region of caudal appendix; single median and postcloacal papilla.

Female (Figs, 1), based on 12 adult specimens URCA-P, 387–388: Length 2.2 ± 0.19 mm (1.4–2.6 mm); width at midbody 384 ± 46 (345.3–436.9). Triangular oral opening surrounded by 3 lips, esophagus 241 ± 38 (141–277.6) long; bulb length 106.8 ± 19.8 (54.4–125.1); bulb width 124.6 ± 26 (57.1–149.7); nerve ring 122.1 ± 19.5 (92.9–146.2), from anterior end. Excretory pore prebulbar, 248.2 ± 48.5 (142.9–323.9), from anterior end; median vulvar opening, without prominent lips, 1.2 ± 0.2 mm (0.7–1.4), from anterior end; ovaries prebulbar, with convoluted uterus full of eggs; eggs oval, with thick and punctuated shell with subpolar operculum, 114.94 ± 11.7 (71.8–151.6) long, 51.48 ± 6.4 (33.8–66.8) wide (Figs. 01); tail 303.16 ± 34.9 (230.4–339.3) long.

Taxonomic summary. Type host: Dermatonotus muelleri (Muller’s termite frog; sapo boi); Coleção Herpetológica da Universidade Regional do Cariri (URCA—H 1450, 1451,1574-88; 2201-15; 2699-2711; 3223-25); collection date (February to April of 2012).

Type locality: Sítio colônia—municipality of Exu, Pernambuco State, Brazil, 39º45'W; 07º34'S.

Site of infection: Small and large intestine. Prevalence 14.58%, mean intensity of infection 20.28 ± 13.29.

Specimens deposited: Coleção Parasitológica da Universidade Regional do Cariri, CE, Brazil; Holotype No. URCA- P 386; Allotype No. URCA-P 387; Paratypes, 3 adult females, URCA-P 370.

Etymology: this species is named after Reinaldo José da Silva (Laboratório de Parasitologia de Animais Silvestres, Universidade Estadual Paulista) who made pioneer contributions to the taxonomy and biology of Neotropical parasite nematodes.

Remarks. Parapharyngodon silvoi n. sp. is promptly distinguished from other species of Parapharyngodon by the female ovary that does not reach the esophageal bulb and prebulbar excretory pore. From the 57 described species, only P. senisfaciecaudus ( Freitas, 1957b) , P. riojensis ( Ramallo et al., 2002) , and P. duniae ( Bursey & Brooks, 2004) have an ovary not coiled around the esophagus. The new species can be differentiated from these by an anterior cloacal lip smooth (echinate in P. duniae , P. riojensis P. senisfaciecaudus ; Pereira et al., 2011) and smaller females, with length 1.4– 2.6 mm and width 349–436 ( P. senisfaciecaudus 9.9–10.7 mm and 900–1040; P. riojensis 4.2–5.4 mm and 840–1040; P. duniae 3.8.– 4.5 mm and 318–434). Moreover, males of P. silvoi n. sp. have four pairs of cloacal papillae plus one unpaired papillae, while P. senisfaciecaudus , P. riojensis , and P. duniae have three pairs of caudal papillae and one unpaired papilla. Furthermore, P. riojensis and P. senisfaciecaudus have spicules larger than the new species (90–110; 88–100, respectively) and P. duniae have spicules smaller than P. silvoi n. sp. (40–49). The only species which have four pairs plus one unpaired papillae is Parapharyngodon sceleratus (Travassos, 1923) , and the new species can be differentiated, besides female morphology, by possessing only one pair of precloacal and two pairs of postcloacal papillae, whereas P. scleratus have two precloacal pairs and one postcloacal pair of papillae ( Freitas, 1957a).

Figures

FIGURE 1. Parapharyngodon silvoi n. sp. (A) male, entire and ventral view. (B) female, entire ventral view. (C) male, posterior end, ventral view. (D) excretory pore. (E) female, anterior end, en face view. (F) copulatory spicule. (G) female egg.