Labiobulura (Labiobulura) quentini, Smales, Lesley R., 2009

Smales, Lesley R., 2009, A review of the nematode genus Labiobulura (Ascaridida: Subuluridae) parasitic in bandicoots (Peramelidae) and bilbies (Thylocomyidae) from Australia and rodents (Murinae: Hydromyini) from Papua New Guinea with the description of two new species, Zootaxa 2209, pp. 1-27 : 21-25

Labiobulura (Labiobulura) quentini sp.nov.

( Figs 79–93 , 95 D, 98G, H, 99)

Type host. Isoodon obesulus (Shaw) .

Site in host. Caecum, colon.

Material examined. Holotype male, allotype female from Isoodon obesulus, Manjimup , Western Australia, coll. T. Foley, 16. ix. 1993 SAM AHC 33218, 44994; paratypes 9 males, 10 females, same data, SAM AHC 44995.

Etymology. The name reflects the large amount of work that Dr Quentin has done on this group.

Differential diagnosis. Labiobulura (L.) quentini differs from all congeners except L. (L.) baylisi , L. (L.) inglisi and L. (L.) peramelis in having interlabia. Closest to L. inglisi in the proportions of the buccal apparatus, the placement of the cephalic papillae and amphids, and the narrow cervical alae it can de distinguished by the shapes of the labial lobes and denticles and the shapes of the chordal and radial lobes of the pharyngeal portion of the oesophagus.

Description. General: Robust, medium sized worms. Cuticle with annulations; cervical alae narrow. Mouth opening bounded by 6 labial lobes, 4 submedians triangular in outline, each with double cephalic papilla on base, 2 laterals longer, sub chordate, labial grooves form rounded base, each with amphid on base; 4 narrow strap like, 2 triangular interlabia without papillae, oriented 3 dorsally, 3 ventrally; proximal end of each lateral lobe and the rectangular interlabial lobes with tri lobed denticle. Buccal capsule circular in cross section, separated from pharyngeal portion by fine transverse ridge; pharyngeal portion of the buccal apparatus longer than wide. Pharyngeal lobes cuticularized; 3 larger rectangular chordal lobes, 3 smaller bilobed radial lobes, project anteriorly into buccal cavity. Chordal and radial lobes neither helical nor spiral; peripheral lobes form cup for chordal and radial lobes, one peripheral lobe larger, extending into buccal cavity. Oesophagus widens gradually to terminal bulb, about1/6 to 1/9 body length. Nerve ring surrounds anterior oesophagus; excretory pore posterior to nerve ring.

Male: Length 8–1 (9.2) mm; width 204–442 (337). Buccal apparatus maximum dimensions 59.4–81.6 (59.4) long, 36–46.2 (37.2) wide; buccal capsule 11.9–18.7 (17) long, 11.9–23.8 (20.1) wide. Oesophagus 1309–1649 (1497) long; bulb 188–221 (207) long, 168–248 (214) wide. Nerve ring 307–402 (379), excretory pore 429–717 (573) from anterior end. Spicules similar, slender with longitudinal ridge, transverse striations along one edge, proximal ends simple, distal tips pointed 1460–2150 (1873) long, about 1/5 body length. Gubernaculum with sides extending anteriorly, 132–191 (170) long. Tail 165–241 (201) long. Sucker pre cloacal, elongate, without cuticular elaborations 580–810 (696) from tail tip; 11 pairs caudal papillae, 3 pairs pre cloacal, 2 pairs at level of cloaca, 6 pairs post cloacal.

Female: Length 12–15 (13.8) mm; width 340–442 (403). Buccal apparatus maximum dimensions, 75.9– 89.1 (81.8) long, 42.9–62.7 (48.3) wide; buccal capsule 20.4–23.8 (21.8) long, 25.5–34 (27.9) wide. Oesophagus 1410–1836 (1549) long; bulb 215–281 (244) long 248–268 (261) wide. Nerve ring 409–475 (437); excretory pore 530–799 (645) from anterior end. Vulva simple, unornamented, in anterior half of body, 4375–7480 (5346) from anterior end, about 1/2.5 body length. Tail elongate, tapering to conical tip 952–1275 (1128) long. Eggs embryonated, thin shelled, sub globular 49.5–69.3 (59.95) by 49.5–69.3 (56.1).

Distribution and host. Labiobulura (L.) quentini has been found only in a single individual of I. obesulus from Manjimup in the south western corner of Western Australia.

Remarks. Labiobulura (L.) quentini differs from all congeners except L. (L.) baylisi , L. (L.) inglisi and L. (L.) peramelis in having 6 labial and 6 interlabial lobes. Labiobulura quentini differs from L. baylisi in having neither a nuchal constriction nor papillae on the mid region of the labial lobes and narrow cervical alae, and from L. peramelis by the shape of the rectangular interlabial lobes, with constricted bases in L. peramelis , narrow strap like in L quentini , papillae on rather than below the labial lobes and narrow not wide cervical alae. Labiobulura quentini differs from L. inglisi in having sub chordate not broad tipped lateral lobes, narrow, strap like rectangular inter labial lobes, rectangular not long and elongated chordal lobes and tri lobed not quadri lobed denticles.

Figures

FIGURE 95. Scanning electron micrographs of anterior ends of Labiobulura (Labiobulura) spp. A, L. baylisi; B, L. inglisi; C, L. peramelis; D, L. quentini. Scale bars: 20 μm.

FIGURES 79 – 93. Labiobulura (Labiobulura) quentini sp. nov. 79, anterior end male, lateral view; 80, cephalic end, en face view; 81, cephalic end, optical section dorso-ventral view; 82, mid buccal apparatus, hand cut transverse section; 83, hand cut longitudinal section, buccal apparatus showing chordal and radial lobes; 84, cephalic end, optical section lateral view; 85, ala, hand cut transverse section. 86, spicule, proximal end; 87, spicule shaft; 88, spicule tip, lateral aspect; 89, vulva, lateral view; 90, gubernaculum, lateral view; 91, male tail, lateral view; 92, male tail, ventral view; 93, female tail, lateral view. Scale bars: 79, 92, 93, 200 µm; 80 – 84, 86 – 88, 90, 25 µm; 85, 89, 91, 50 μm.