Parasabanema sene, Smales, 2020

Smales, Lesley, 2020, Gastrointestinal nematodes of Paramelomys levipes and P. mollis (Rodentia Muridae) from Papua, Indonesia and Papua New Guinea with the descriptions of three new genera and nine new species (Nematoda), Zootaxa 4861 (4), pp. 544-572 : 565

Parasabanema sene n. sp.

( Figs 9 A–J)

Type host. Paramelomys mollis (Thomas)

S ite in host. Small intestine.

Type specimens. Holotype male, allotype female, paratypes 5 males, 8 females BBM NG 102174B, from Paramelomys mollis from southeast slopes Mt Giluwe , 2300 m, Southern Highlands Province, Papua New Guinea; coll. A. B. Mirza, 25. v. 1973.

Other material examined. From P. mollis From Papua New Guinea, Southern Highlands Province, 8 males, 12 females southeast slopes Mount Giluwe , BBM NG 102171 B, 102172 D, 192235 B.

Etymology. The species name is a local dialect name for the host.

Description. General: Relatively robust worms, usually coiled. Cephalic vesicle prominent with about 11 transverse annulations. Buccal capsule vestigial, mouth opening triangular with rudimentary lips; cephalic and labial papillae not seen, 2 lateral amphids. Oesophagus claviform, nerve ring excretory pore and deirids not seen.

Synlophe: (based on sections from 5 worms) Longitudinal pointed ridges extend from posterior margin of cephalic vesicle to anterior to bursa or vulva; 28–30 ridges; 28–30 in males, 30 in females, in mid body. Left side dilated. Axis of orientation of ridges sub frontal; 12–15 ridges dorsal side, 14–16 ventral side. Ridges more or less equal in size, no consistent differences in number or size of ridges between anterior and posterior, males and females.

Male: (measurements of 8 specimens) Length 3.1–4.3 (3.5) mm, maximum width 40–54 (47). Cephalic vesicle 40–43 (40) long. Oesophagus 250–310 (281) long; nerve ring, deirids and excretory pore not seen. Bursa dissymmetrical, right lobe larger; pattern of rays 2–3. Dorsal trunk symmetrical divided at about 1/2 its length, terminal divisions rays 9, 10 symmetrical, rays 8 arising from dorsal trunk at about same level, not reaching margins of bursa; lateral rays 6 smaller than rays 5, 4, reaching margin of bursa, rays 3, 2 arise from common trunk, reaching margin of bursa. Genital cone prominent, ventral lip longer, rectangular. Spicules equal, filiform, tips curved, 250–310 (281) long; spicule to body length ratio 8 %. Gubernaculum 20 (1 measurement).

Female: (measurements of 12 specimens) Length 4.0–7.8 (5.5) mm, maximum width 46–63 (48). Cervical vesicle 24–43 (37) long. Oesophagus 250–360 (314) long; nerve ring, deirids, excretory pore not seen. Vulva opens 60–115 (106) from tail tip; tail tightly flexed ventrally. Ovejector monodelphic with infundibulum longest element, 80–120 (98) long, sphincter 20–30 (27), shortest element, vestibule 40–50 (47), vagina 30–35 (31) long. Tail conical with pointed tip, 17–24 (21) long. Eggs thin shelled, ellipsoidal, 4 eggs in utero, 62.7–72.6 (63.3) long, 33.0–42.9 (37.2) wide.

Remarks. The new species can be placed in the genus Parasabanema because it possesses the suite of characters that distinguishes the genus, including a synlophe with more or less equal sized sub frontal ridges, with a left cuticular dilatation, without a carene and a bursa with the right lateral lobe larger and rays 3 longest ( Smales & Heinrich 2010). Parasabanema sene n. sp. can be differentiated from P. szalayi Smales & Heinrich, 2010 in having fewer than 45 ridges in the synlophe, the dorsal trunk divided at about ½ its length and shorter spicules, 250—310 compared with 380–503 long, and the female ovejector with the vestibule shorter, not the same length as the infundibulum and up to 4 eggs in utero compared with 13. Parasabanema sene occurs in Paramelomys mollis and P. szalayi in Paramelomys rubex (see Smales & Heinrich 2010).

Figures

FIGURE 9. Parasabanema sene sp. n. 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, as are the lateral rays of the bursa (right rays with superscripts). A. Female, anterior end lateral view, cervical vesicle bent dorsally; B. Male, cervical vesicle lateral view; C. Male, mid body transverse section; D. Female, mid body transverse section; E. Male, spicule anterior end; F. Male, spicule tips; G. Male, ventral view showing gubernaculum, spicule tips and genital cone; H. Female, towards posterior end transverse section; I. Female, posterior end lateral view showing ovejector; J. Male, bursa partially unrolled. Scale bars in µm: A. I, J, 50; B–H, 25.