Syphacia (Segienamsyphacia) yuniae, Dewi & Hasegawa & Asakawa, 2014

Dewi, Kartika, Hasegawa, Hideo & Asakawa, Mitsuhiko, 2014, Description of two new species of Syphacia (Nematoda: Oxyuridae) collected from Eropeplus canus (Rodentia: Muridae), an endemic rat of Sulawesi, Indonesia, with proposal of new subgenera, Raffles Bulletin of Zoology 62, pp. 647-654 : 650-653

Syphacia (Segienamsyphacia) yuniae , new species

( Figs. 19–36 )

Material examined. Holotype male and allotype female (MZBNa 626), 10 males and 10 females paratypes (MZBNa 627), Lambanan, Sulawesi, Indonesia, coll. H. Hasegawa, 31 July 1992.

Description. General: With subgeneric characteristics defined above. Small sized worms with cuticle striated transversely. Cephalic vesicle weakly developed. Amphidial pores slightly closer to subventral cephalic papillae than to subdorsal ones. Oesophagus with corpus, distinct isthmus and terminating in spherical bulb. Nerve ring at middle of oesophageal corpus. Deirid not seen.

Male (holotype and 10 paratypes): Posterior body bent ventrally; length 1.20 [1.00–1.25] (1.14) mm, maximum width 88 [70–86] (81). Mouth triradiate, surrounded by three lips; distance between amphidial pores 8.2–11.5 (n=2); lateral alae large; total oesophagus including pharynx, corpus and bulb 248 [247–277] (254) long: pharynx 10 [9–11] (10) long and 13 [10–13] (11) wide, corpus 182 [170–200] (179) long and 32 [24–29] (26) wide, isthmus [13–15 (13)] long and 16 [13–15] (14) wide at narrowest level, bulb 57 [47–56] (52) long by 61 [50–55] (54) wide; nerve ring and excretory pore 88 [100–107] (109) and 412 [376–435] (404) from anterior end, respectively; three mamelons on ventral surface of body provided with many transverse bands, each with central rows of spinules: anterior mamelon 72 [60–77] (64) long, middle mamelon [35–54] (46) long and posterior mamelon 35 [24–38] (32) long; distance from cephalic end to anterior edges of anterior, middle and posterior mamelons 642 [592–726] (652), 756 [661–857] (758) and 907 [769–962] (867), respectively; spicule single, thin, needle-shaped, relatively long, 83 [64–82] (73) long [i.e. 6.9 [5.5–7.5] (6)% of TBL]; gubernaculum 24 [22–28] (25) long; accessory piece of gubernaculum unornamented, protruded from body 10 [9–12] (10); caudal papillae present in 3 pairs, 2 pairs small, near cloaca, and 1 pair large, post-cloacal, protruding posterolaterally; tail 158 [126–157] (149) long including whip-like process [i.e., 13.2 [10.2–14.3] (13)% of TBL].

Female (allotype and 10 paratypes): Length 2.35 [2.34–2.56] (2.45) mm, width 154 [155–200] (181). Cephalic vesicle present, extending posteriorly to nerve ring. Oral aperture hexagonal. Distance between amphidial pores 16.2–17.8 (n=2). Lateral alae absent; total oesophagus including pharynx, corpus and bulb 378 [273–399] (381) long: pharynx 18 [16–22] (21) long and 28 [18–28] (20) wide, corpus 262 [245–287] (266) long and 50 [44–50] (47) wide, isthmus 24 [18–28] (22) wide at narrowest level, bulb 85 [72–85] (81) long by 91 [83–95] (87) wide; nerve ring 141 [112–148] (141), excretory pore 472 [471–570] (501) from cephalic end; vulva not protruding, 755 [753–853] (811) from cephalic end; vagina and ovejector weakly developed, directed posteriorly; distance between excretory pore and vulva 283 [201–324] (269) [i.e. 12.0 [8.1–12.8] (10.9)% of TBL]. Eggs asymmetrical with one side flattened, having operculum on convex side, closer to equator of egg, shell surface densely pitted, containing embryo with visible oesophagus in uterus, 68–74 (71.5) × 24–28 (25.7); uterus occupying in the middle of body, extending from level of excretory pore to near posterior end of middle 1/3 of body; tail long conical with pointed end, relatively long, 519 [469–540] (520) [i.e., 22.1 [19.4–23.1] (21.1)% of TBL].

Type host. Eropeplus canus Miller & Hollister, 1921 (Sulawesi soft-furred rat) ( Rodentia : Muridae ).

Symbiotype. The type host was deposited to the American Museum of Natural History with accession number M-267755.

Site of infection. Caecum.

Etymology. Subgeneric name was created by combining Indonesian word ‘Segi enam’ meaning hexagonal, symbolising hexagonal oral shape in female, and Syphacia . Species epithet is dedicated to Ms. Yuni Apriyanti, to whom we are greatly indebted on preparation of specimen for SEM observation.

Remarks. This is also a typical member of the genus Syphacia Seurat, 1916 by having three mamelons in males (Petter & Quentin, 1971; Hugot, 1988). Among the three subgenera recognised, it is close to the subgenus Syphacia by lacking cervical alae and developed deirids, and by having an unornamented accessory piece of the gubernaculum and vesicular lateral alae ( Hugot, 1988). However, the hexagonal oral shape in the female has not been known for other members of the subgenus Syphacia species and other two subgenera. Hence new subgenus is proposed. Similar oral shape has been known in Oxyuris , Brasilnema Moravec et al., 1992 , Paraustroxyuris Mawson, 1964 , Petronema Hugot, 1983 , Royandersonia Moravec & Van As, 2004 among the oxyuroids parasitic in vertebrates ( Petter & Quentin, 1976; Gibbons, 2010). The egg operculum position is also characteristic because most congeners of Syphacia have an egg operculum closer to pole ( Quentin, 1971; Petter & Quentin, 1976; Hugot, 1988).

Distribution. Lambanan, Sulawesi, Indonesia (present study)

Figures

Figs. 19–30. Syphacia (Segienamsyphacia) yuniae, new species from Eropeplus canus in south Sulawesi, Indonesia. 19, male, holotype, lateral view; 20, cephalic end of male, apical view; 21, midbody in cross section of male; 22, midbody in cross section of male, higher magnification; 23, posterior portion of male, ventral view; 24, posterior portion of male; lateral view; 25, spicule and gubernaculum, lateral view; 26, female, lateral view; 27, cephalic end of female, apical view; 28, midbody in cross section of female; 29, egg; 30, excretory pore and vulva, showing poorly developed vagina

Figs. 31–36. SEM Syphacia (Segienamsyphacia) yuniae, new species from Eropeplus canus in south Sulawesi, Indonesia. 31, cephalic end of female, apical view; 32, cephalic end of female, apical view, higher magnification; 33, egg; 34, enlarged view of eggshell surface; 35, caudal papilla of male, lateral view; 36, mamelon, ventral view.