Hughjonestrongylus pervulgatus, Smales, 2019

Smales, Lesley, 2019, Gastrointestinal nematodes of Paramelomys platyops (Rodentia: Muridae) from Papua Indonesia and Papua New Guinea with the descriptions of a new genus and five new species of Heligmonellidae (Nematoda: Trichostrongylina) and a key to the species of Hughjonestrongylus, Zootaxa 4679 (1), pp. 107-125 : 115-117

Hughjonestrongylus pervulgatus sp. nov.

( Figs 29–44 )

urn:lsid:zoobank.org:act:1B8D1317-21F9-4478-B8A1-F14D620B6405

Type host. Paramelomys platyops (Thomas) .

Site in host. Small intestine.

Material examined. Holotype male AM W.51740 allotype female AM W.51741 from Paramelomys platyops from Kampong Korido , Supiori Island, Papua, Indonesia (00° 50´S 135° 36´E); coll A. Szalay, 26. Ix. 1992; paratypes 6 males, 8 females, same data AM W.51742.

Other material examined. From Paramelomys platyops from Papua New Guinea, Madang Province; 2 males, 2 females, 5k north Wanuma BBM NG 103839 B; From Melomys sp., from Papua, Indonesia, Maluku Province, 3 males, 3 females, Aru Island AM W.51745.

Etymology. The specific name is given in reference to the species occurring on off shore islands as well as mainland New Guinea.

Description. General: Small worms, slightly or tightly coiled: cephalic vesicle annulations not observed, buccal capsule vestigial, annular. Mouth opening triangular with rudimentary lips; labial and cephalic papillae not observed. Oesophagus claviform. Nerve ring in region of anterior half of oesophagus, deirids and excretory pore at about same level in region of posterior third of oesophagus.

Synlophe: (based on sections from 8 worms) of pointed longitudinal continuous ridges extending from posterior margin of cephalic vesicle to immediately anterior to bursa or vulva; 20 ridges in anterior body female; 27–29 in mid body male, 25–26 in mid body female; 27–30 posterior body male, 25–30 posterior body female. Ridges markedly different in size.Axis of orientation oblique from right ventral to left dorsal in mid body, losing orientation posteriorly; 11–12 ridges dorsal side, 13–17 ventral side. Left ridge distinct from ridge 1´; mid left and mid right ridges largest; left ridge 2´smaller than 1´, ventral ridges 3´–14´about same size, dorsal ridges 1–5 decreasing in size, right ridges 6–10, 11/ 12 increasing in size; ridges reduced in size and size gradient lost posteriorly.

Male: (measurements of 9 specimens) Length 2100–2700 (2500), maximum width 67.0–83.0 (77.9). Cephalic vesicle 37–46 (41) long. Oesophagus 340–370 (354) long; nerve ring 150 (1 measurement) from anterior end; deirids and excretory pore not observed. Bursa dissymmetrical, left lobe larger, pattern of rays 2–3, dorsal lobe shorter than laterals, dorsal ray symmetrical, divided at about 2/3 its length, each branch dividing again at tip, terminal divisions rays 9, 10 symmetrical, rays 8 dissymmetrical, arising from dorsal trunk at about same level; lateral rays 6 curved dorsally, 4, 5 ventrally, rays 4 largest, rays 2, 3 diverge ventrally, reaching margin of bursa. Genital cone short, rounded, ventral and dorsal lips about same size, dorsal lip with paired papillae 7 slightly elongated. Spicules equal, filiform, 310–350 (327) long, spicule to body length ratio 13%, tips simple. Gubernaculum 24.0–26.5 (25.6) long.

Female: (measurements of 10 specimens) Length 2250–2600 (2300), maximum width 51.0–99.0 (78.2). Cephalic vesicle 33–50 (41) long. Oesophagus 280–410 (349) long; nerve ring not observed, deirids 210, excretory pore 220 (1 measurement) from anterior end. Vulva opens 102, 106 from tail tip; large plug of material covers ventral surface from vulva to tail tip in most specimens, some specimens with praepuce; tail more or less flexed ventrally. Ovejector monodelphic, with sphincter, 30, shortest element, vagina 35, vestibule 50, infundibulum, 90, longest element (1 measurements). Tail conical with pointed tip 51.0–56.0 (53.3) long. Eggs thin-shelled ellipsoidal, 4 in utero, 63.0–69.0 (65.2) long by 33.0–36.3 (33.9) wide.

Remarks. Although the specimens were in poor condition, sufficient morphological information could be gathered to assign them to a genus and describe them as a new species. The new species could be placed in the genus Hughjonestrongylus because it has a synlophe showing the same arrangement of pointed ridges as described in the diagnosis of Durette-Desset and Digiani (2015), with a dissymmetrical bursa, a type 2–3 pattern of bursal rays and the dorsal ray divided within the distal quarter.

In having a synlophe of 25–29 ridges in the mid body and 25–30 posteriorly Hughjonestrongylus pervulgatus n. sp. is closest to the type species H. ennisae ( Smales & Heinrich, 2010) with 26–29 ridges, H. implexus ( Smales, 2008) with 26–27 ridges and H. woolleyae ( Smales, 2017) with 25–26 ridges on the synlophe at the mid body ( Smales 2008, 2017; Smales & Heinrich 2010). Hughjonestrongylus pervulgatus further differs from H. ennisae in spicule length (mean length 327 compared with 386), the form of the right spicule tip, (simple not trifid), gubernaculum length (24–26.5 compared with 37.5), the form of the female posterior end (with large cement plug not twisted dorsally then ventrally) and a smaller number of eggs in utero ( Smales & Heinrich 2010); from H. implexus in having shorter spicules (310–350 compared with 450–700), the form of the spicule tips (simple, not complex) and the proportions of the ovejector, with the infundibulum the longest element ( Smales 2008); from H. woolleyae in having relatively longer spicules (mean length 327, 13.08% body length compared with 339, 8.3% body length), a symmetrical dorsal ray, a shorter gubernaculum (24–26.5 compared with 37) and in the shape of the posterior end of the female (not swollen at the level of the ovejector but with a large cement plug) and fewer eggs in the uterus ( Smales 2017).

Figures

FIGURES 29–44. Hughjonestrongylus pervulgatus n. sp. In all illustrations of the synlophe in transverse section the dorsal aspect of the body is oriented towards the top of the page and the left side of the nematode to the left of the page. The dorsal and ventral (numbers with superscripts) ridges are numbered. 29. Female anterior end, lateral view; 30. Male cephalic end lateral view, showing synlophe ridges; 31. Female transverse section anterior body; 32. Male transverse section, anterior body; 33. Spicule tips; 34. Genital cone, dorsal view; 35. Female transverse section, mid body; 36. Male transverse section, mid body; 37. Female posterior end lateral view, showing ovejector; 38. Female, posterior end ventral view showing plug of cement-like material; 39. Female transverse section, posterior body; 40. Male transverse section, posterior body; 41. Bursa, left lateral lobe, rays numbered; 42. Dorsal ray; 43. Gubernaculum an spicule tips, dorsal view; 44. Bursa, right lateral lobe. Scale bars in µm: 29, 38, 100; 30–36, 39–44, 25; 37, 50.