Syphacia (Syphacia) niobe, Smales, L. R., 2016

Smales, L. R., 2016, The gastrointestinal helminths of Rattus niobe (Rodentia: Muridae) with descriptions of two new genera and three new species (Nematoda) from Papua New Guinea and Papua Indonesia, Zootaxa 4117 (2), pp. 183-197 : 186-189

Syphacia (Syphacia) niobe sp. nov.

( Figs 1–14 )

Type host. Rattus niobe (Thomas)

Site in host. Caecum.

Material examined. Holotype male AM W.48446 allotype female AM W.48447 from Rattus niobe from Siyoubrig (1° 06´S 133° 56´E), Mokham area, Arfak Mountains, Papua, coll. T. Flannery 10. x. 1992; 10 males, 138 females paratypes, same data W.48448.

Other material examined. From R. niobe : Central Province: 2 males, 64 females, Mt Yule (8° 12´S 146° 46´E), coll. A. Allison 14. x. 2013, BBM NG 185946, 185947, 185948, 185949. Sanduan Province West Sepik region: 26 males, 403 females, Dokfuma Star Mountains (5° 01´S 141° 07´E), coll T. Flannery 3. iv. 1987, AM W.48455, W.48456, W.48457, W.48458, W.48459, W.48462, W. 19 males, 195 females, hill south of Tifalmin (5° 07´S 141° 25´E), coll. T. Flannery 15. iv. 7, AM W.48451, W.48454, W.48456, W.48460 14 females, Kamptamen, south of Hindenburg Wall (5° 10´S 141° 16´E), coll. T. Flannery 13. iv. 1987, AM W.48450; 95 females, Ofekaman, Telefomin area (5° 05´S 141° 35´E), coll. T. Flannery 13. ii. 1984, AM W. 48449; 1 male, 22 females, Dumae Creek 2.3 k north, 0.4 k west Aguan (9° 90´S 149° 33´E), coll. A. Engelis Jnr 1. iii. 1985, BBM NG 109274; 20 females, Goyou Ravine 2 k north 0.1 k west Aguan (9° 91´S 149° 38´E), coll. A. Engelis Jnr 6. iii. 1985, BBM NG 109277; 1 male, 2 females, Garatin Ridge, 2.5 k north 1.5 k west Aguan (9° 90´S 149° 37´E), coll. A. Engelis Jnr 7. iii. 1985, BBM NG 109286. Milne Bay Province: 7 females, Munimun Village (9° 53´S 149° 23´E), coll. P. German 11. viii. 1992, AM W.48453. Western Province: 11 females, Mabiomskin near Ok Tedi mine site, coll. T. Flannery 12. v. 1992, AM W.48461. Simbu Province: 19 males, 199 females Mount Wilhelm coll. A. B. Mirza 23. ix. 1971, BBM NG 100553, 100542, 100543, 100544, 100545,

Etymology. The species name refers to the host species name.

Description. General: Mouth opening surrounded by 3 weakly defined lips, 1 dorsal 2 subventral. Cephalic plate round; 4 cephalic papillae, 2 dorsally, 2 ventrally, and 2 amphids, placed laterally between cephalic papillae, at edge of cephalic plate. Cephalic vesicle present, cervical alae and lateral alae absent in both sexes. Deirids not seen. Oesophagus with pharynx, corpus and posterior bulb.

Male: (measurements of 15 specimens) Body length 0.82–1.90 (1.22) mm, width 67.5–114.0 (80.5). Distance between amphids 20. Oesophagus total length 167–244 (197); bulb 25-92 (52) long, 38–83 (51) wide. Nerve ring 66–115 (84), excretory pore posterior to oesophago-intestinal junction, 265–363 (331) from anterior end. Mamelons, 3, well developed with transverse striations, on ventral posterior body; 349–643 (531) from anterior end to anterior edge of anterior mamelon, to middle mamelon 429.0–772.2 (621.1), to posterior mamelon 511.5– 912.2 (719.1); posterior mamelon to cloaca 25.0–75.0 (53.3); anterior mamelon 47.5–79.2 (50.1), middle mamelon 47.5–75.0 (55.5), posterior mamelon 27.5–50 (44.4) long. Posterior extremity curled ventrally. Spicule thin, filiform, 44.2–61.2 (52.8) long; gubernaculum stout, hook shaped 11.3–20.0 (16.3) long, accessory piece relatively thin, unornamented. Caudal papillae in 3 pairs, 2 pairs ad cloacal, 1 pair larger postero- lateral papillae. Tail total length 95.0–125.5 (109.3), whip like appendage 72.5–92.4 (78.7).

Female: (measurements of 17 specimens) Body length 1.8–3.2 (2.4) long, 125–425 (151) wide. Distance between amphids 30. Oesophagus total length 260.0–330.0 (294.6); bulb 59.4–95.7 (75.2) long, 49.4–89.1 (72.8) wide. Nerve ring 90–115 (102), excretory pore usually posterior to oesophago-intestinal junction, 200–410 (366) from anterior end. Vulva salient, without ornamentation, 482–677 (578) from anterior end. Tail thin, elongated, attenuated, 300–600 (366). Eggs oval, asymmetrical, smooth shelled, operculated, 80.0–92.4 (84.6) long, 25.0– 33.0 (29.8) wide.

Remarks. This new species belongs in the genus Syphacia Seurat because it possesses the suite of characters, including 3 mamelons, proposed by Hugot (1988) to distinguish the group and in the sub genus Syphacia based on the round cephalic plate, lack of cervical alae and lack of developed deirids ( Hugot 1988). Following the key to species of Syphacia occurring in the Australian bioregion of Dewi et al. (2014) Syphacia (Syphacia) niobe n. sp falls within the group of species with a round cephalic plate and is closest to S. (S.) paruromyos Dewi & Hasegawa, 2012 in the form of the female tail and to S. (S.) semiadii Dewi, Asakawa & Fitriana, 2014 in the length of the male and female tails (male 95–125 and female up to 600 long)( Dewi et al. 2014). Syphacia (S.) niobe differs from S. (S.) paruromyos in the absence of lateral alae in the male, as well as having the excretory pore and first mamelon more anterior (265–365 compared with 544–860 and 349–643 compared with 760–1190 from the anterior end respectively), a smaller gubernaculum (12.5–20.0 compared with 26–37) and larger smooth shelled eggs compared with smaller pitted shelled eggs (80–92 compared with 64–72 long). Syphacia (S.) niobe differs from S. (S,) semiadii in the shape of the female tail, in lacking teeth-like structures associated with the lips, in having shorter spicules (44–61 (53) compared with 61–78 (70) long) and larger smooth shelled eggs compared with smaller pitted shelled eggs (80–92 compared with 68–70 long) ( Dewi & Hasegawa 2012; Dewi et al. 2014). Of the four other species with round cephalic plates occurring in the region S. (S.) niobe differs from S. (S.) lorentzimyos in lacking cervical and lateral alae, in having the first mamelon with a thick muscular body wall, and a longer male tail (95– 125 compared with 65–72); from S. (S.) mamelonitenuis Smales, 2010 in not having the first mamelon poorly defined, and a longer tail with a whip like appendage (95–125 compared with 65–72) (Smales 2010); from S. (S.) rifalii Dewi & Hasegawa 2010 in lacking lateral alae, having a longer tail (95–125 compared with 35– 60 male, 300–600 compared with 181– 274 female), shorter spicules (44–61 compared with 61–70) and larger eggs (80–92 compared with 68–70 long) ( Dewi & Hasegawa 2010); from S. (S.) taeromyos Dewi & Hasegawa, 2012 in having weakly defined lips not protruding, lacking lateral alae, the anterior mamelon not elongated, about the same size as the other 2 mamelons, shorter spicules (44–61 compared with 62–77) a longer male tail (95–125 compared with 64–71) and larger eggs (80–92 compared with 57–62 long) ( Dewi & Hasegawa 2012). Syphacia (S.) paruromyos , S. (S.) rifalii , S. (S.) semiadii and S. (S.) taeromyos are found in endemic murine genera from Sulawesi, Indonesia and S. (S.) lorentzimyos and S. (S.) mamelonitenuis in an endemic genus from Papua New Guinea (Smales 2010; Dewi & Hasegawa 2010, 2012; Dewi et al. 2014).

Syphacia (S.) longaecauda Smales, 2001 and Syphacia (S.) coccymyos Smales, 2011 have also been reported as occurring in endemic murine genera from New Guinea and can be distinguished from S. (S.) niobe in having oval, not round cephalic plates and lateral alae ( Smales 2001, 2011). Species of Syphacia occurring in species of Rattus in the region are the cosmopolitan S. (S.) muris Yamaguti, 1935 occurring in several species of Rattus , S. (S.) sulawesiensis Hasegawa & Tarore, 1996 found in R. xanthurus Gray from Sulawesi and S. (S.) australasiensis Smales, 2004 found in R. leucopus from Papua New Guinea. Each of these species differs from S. (S.) niobe in the shape of the cephalic plate and the absence of lateral alae in both males and females ( Hasegawa & Tarore 1996; Smales 2004).

Figures

FIGURES 1 – 14. Syphacia niobe n. sp. 1. Female anterior end, lateral view; 2. Female, en face view; 3. Male, en face view; 4. Male, lateral view; 5. Female cephalic end, lateral view; 6. Female cephalic end, ventral view; 7. Male cephalic end, lateral view; 8. Vagina, lateral view; 9. Female mid body, transverse section. 10. Male posterior end, ventral view; 11. Egg; 12. Female tail, lateral view; 13. Spicule, gubernaculum and accessory piece, lateral view. 14. Male posterior end, lateral view; Scale bars in µm: 1, 4, 100; 2, 3, 12, 50; 5, 6, 8 – 11, 25; 7, 14, 12.5, 13, 10.