Pogonomystrongylus domaensis, Smales, L. R., 2014

Smales, L. R., 2014, Gastrointestinal helminths (Cestoda, Chabertiidae and Heligmonellidae) of Pogonomys loriae and Pogonomys macrourus (Rodentia: Muridae) from Papua Indonesia and Papua New Guinea with the description of a new genus and two new species, Zootaxa 3889 (1), pp. 92-106 : 102

Pogonomystrongylus domaensis sp. nov.

( Figs 36–48 )

Type host. Pogonomys loriae Thomas

Site in host. Small intestine.

Material examined. Holotype male, allotype female from Pogonomys loriae, Doma Peaks, 2400 m, Southern Highlands Province, Papua New Guinea, coll. A. B. Mirza and Bin Yuo, 13. iv. 1978, BBM NG 105735 C; paratypes, 18 males, 40 females, same data.

Etymology. The species name is derived from the type locality.

Description. General: Small coiled nematodes, cephalic vesicle prominent with 11–13 annulations, buccal capsule vestigial. Mouth opening triangular, with rudimentary lips; cephalic and labial papillae not seen, 2 lateral amphids. Oesophagus claviform, nerve ring not seen, deirids dome shaped, at about same level as excretory pore.

Synlophe: Longitudinal cuticular ridges extend from posterior margin of cephalic vesicle to anterior to bursa or vulva; 7–8 in anterior, 9–11 in mid body, in posterior; axis of orientation of ridges sub frontal: 3–4 ridges anterior dorsal side, 4–5 ridges anterior ventral side, 4–5 ridges mid dorsal side, 5–6 ridges mid ventral side; 2–4 ridges posterior dorsal side 2–3 ridges posterior ventral side; ridge 1’ largest in anterior and mid body, ridges 2’–5’, 2–6 increasing in size.

Male: Body length 2.2–2.9 (2.6) mm, maximum width 85–114 (100.7). Cephalic vesicle 44.2–57.8 (46.7) long. Oesophagus 300–420 (390) long; nerve ring not observed; deirids 230–350 (266); excretory pore 230–360 (269.5) from anterior end. Bursa asymmetrical right lobe slightly larger, with dorsal cleft; dorsal lobe shorter than laterals. Dorsal ray symmetrical, divided at about 1/2 length, terminal divisions, rays 9, 10 symmetrical; rays 8 arising from dorsal ray at same level, reaching margin of bursa; rays 4, 5, 6 with common stem, rays 6 curve posteriorly, rays 4, 5 more or less straight, rays 2, 3 diverge distally, reaching margin of bursa. Genital cone not prominent. Spicules equal, filiform, 180–240 (196) long, tips simple, slightly curved. Gubernaculum 42.5–52 (47.9) long.

Female: Body length 2.75–3.35 (3.7) mm, maximum width 99–132 (104.5). Cephalic vesicle 42.5–59.5 (47.2) long. Oesophagus 270–390 (352) long; nerve ring not observed, deirids 135– 245 (207); excretory pore 135–250 (210) from anterior end. Posterior end with prepuce. Vulva opens 80–145 (107.3) from tail tip. Ovejector monodelphic, vagina 25, 30, vestibule 20, 30, about same length, sphincter 60, 75, infundibulum 50, 60 long. Tail reflected ventrally, 18–32 (22.2) long, conical ending in conical knob. Eggs thin shelled, ellipsoidal, up to 5 in utero, 66.0–79.2 (77.28) by 33.0–39.1 (37.75).

Remarks. A heligmonellid parasite of a hydromyin rodent from Papua New Guinea Pogonomystrongylus gen. nov. has all the characteristics of the subfamily Nippostrongylinae except that the orientation of the synlophe ridges is sub frontal rather than sagittal (Durette-Desset 1983). The features of the synlophe; up to 10 ridges, ridge1’ largest, pattern of distribution of ridges dorsally and ventrally, gradation of sizes of anterior and mid body ridges, and subfrontal orientation, distinguish the genus from all others in the sub family. In particular Pogonomystrongylus can be distinguished from all the genera presently known from the Sunda and/or Sahul Regions as follows: The genera Mawsonema, Nippostrongylus , Odilia and Paraheligmonelloides all have a type A carene as defined by Durette-Desset (1983). The genera Helligmonoides and Maxomystrongylus have a type B carene as defined by Durette-Desset (1983). The genera Hasanuddinia with an oblique axis of orientation of the ridges, Bunostrongylus with both pointed and rounded ridges, Melomystrongylus with an hypertrophied ventral ridge anteriorly, Montistrongylus with an oblique axis of orientation of the ridges and Parasabanema with a large number of small ridges, all lack a carene. Of the genera known only from the Oriental and Sunda Regions Orientostrongylus has a primitive arrangement of the synlophe with either no or a type B carene, Malaistrongylus has left and right dilatations of the synlophe which has more than 30 ridges and Rattustrongylus and Sabanema , both lacking a carene, have a small number and a large number of ridges respectively ( Durette-Desset, 1970a, b; Ow Yang et al. 1983; Hasegawa & Mangali 1996; Hasegawa & Syafruddin 1994b, 1997; Hasegawa et al. 1999; Smales 2009; Smales & Heinrich 2010).

Figures

FIGURES 36 – 48. Pogonomystrongylus damaensis n. gen., n. sp. 36. Female, anterior end, lateral view; 37. Male, transverse section, anterior body; 38. Female, transverse section, anterior body; 39. Female, posterior end, lateral view; 40. Male, transverse section, mid body; 41. Female, transverse section, mid body; 42. Dorsal ray; 43. Female, transverse section, posterior body; 44. Bursa, left lateral lobe; 45. Bursa, right lateral lobe; 46. Genital cone, lateral view; 47. Gubernaculum, lateral view; 48. Spicule tips. Abbreviations: d, dorsal; v, ventral; l, left; r, right; long arrow shows axis of orientation of synlophe. Scale bars in µm: 36, 39, 44, 45, 50; 37, 38, 40 – 43, 46, 48, 25; 47, 12.5.