Labiobulura (Archeobulura) perditus, 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 : 8-11

Labiobulura (Archeobulura) perditus sp. nov.

( Figs 18–31 , 94 A, D, 97C, D, 99)

Type host. Perameles bougainville Quoy & Gaimard.

Site in host. Probably caecum and, or colon.

Material examined. Holotype male, allotype female from Perameles bougainville , South Australia, SAM AHC 14586, 44994; paratypes 20 males, 20 females, AHC 44995.

Other material examined. From Perameles bougainville : 30 males, 40 females, no collection data SAM AHC 14587, 14588, 23029, 33151, 33152, 33153.

Etymology. The species name reflects the likelihood that since the host population in South Australia is now extinct this species is also now extinct.

Differential diagnosis. Labiobulura (A.) perditus differs from all congeners except L. (A.) leptomyidis and L. (A.) peragale in lacking interlabia. It differs from both of these in the morphology of the labial lobes, with truncated distal tips, the position of the cephalic papillae, the shapes of the chordal and radial lobes of the pharyngeal portion of the oesophagus and the proportions of the cervical alae.

Description. General: Robust, medium sized worms. Cuticle with annulations; cervical alae distinct, narrow. Mouth opening bounded by 6 simple labial lobes, triangular in outline; 4 submedians, 2 laterals; double cephalic papillae and amphids below bases of labial lobes. Buccal capsule circular in cross section, separated from pharyngeal portion by fine transverse ridge. Pharyngeal lobes cuticularized; 3 larger chordal lobes rectangular, proximal surface with notch, project anteriorly into buccal cavity, 3 radial lobes shorter, wedge shaped, project anteriorly extending to base of buccal capsule. Chordal and radial lobes neither helical nor spiral; peripheral lobes form cup for chordal and radial lobes. Oesophagus widens gradually to terminal bulb, about1/5.5 to 1/7 body length. Nerve ring surrounds anterior oesophagus; excretory pore posterior to nerve ring.

Male: Length 5–7 (5.6); width 325–358 (345). Buccal apparatus maximum dimensions 35.5–56 (45.8) long, 29–35.5 (32.8) wide; buccal capsule 10.2–16.5 (12.7) long, 15.3–23.8 (18.0) wide. Oesophagus 840– 1200 (1021) long; bulb 162–228 (195) long 172–228 (203) wide. Nerve ring 254–313 (286), excretory pore 363–489 (429.5), from anterior end. Spicules similar, slender with longitudinal ridge, shaft heavily striated transversely along one edge, proximal ends simple, distal tips pointed 1100–1700 (1361) long, about 1/4 body length. Gubernaculum with sides extending anteriorly 142–178 (150) long. Tail 146–214 (167) long. Sucker pre cloacal, elongate, without cuticular elaborations 470–760 (554) from tail tip; 11 pairs caudal papillae, 3 pairs pre cloacal, 2 pairs at level of cloaca, 6 pairs post cloacal.

Female: Length 7–10 (8.9) mm; width 325–525 (346). Buccal apparatus, maximum dimensions, 42.5– 69.5 (49.4) long, 30–40.5 (36) wide; buccal capsule, 8.5–19.8 (13.6) long, 11.9–26.4 (17.2) wide. Oesophagus 1050–1400 (1195) long; bulb 141–248 (202) long 147–261 (218) wide. Nerve ring 335–375 (357); excretory pore 380–655 (483) from anterior end. Vulva simple, unornamented, in anterior half of body, 3910–4930 (4205) from anterior end, about 1/2.1 body length. Tail elongate 570–865 (693) long, tapering to blunt tip. Eggs embryonated, thin shelled, sub globular 62.7-75.9 (67.6) by 56.1–72.6 (61.7).

Distribution and host. Labiobulura (A.) perditus has been found only in Perameles bougainville and only from South Australia. The SAM database does not record any collection data for any of the available material. Hosts were sourced either from the University of Adelaide Zoology Department, (2 hosts), the University of Adelaide Genetics Department (1 host) or the SAM mammal collection (3 hosts). These latter animals have a registration date of 1936 and no locality information. Originally distributed across southern Australia P. bougainville is now limited to islands off shore from the west Australian coast ( Friend 2008). Since the host animals of L. perditus were most probably collected from a South Australian population prior to its extinction and L. perditus has not been found in the extant populations of P. bougainville it is now probably also extinct.

Remarks. Labiobulura (A.) perditus differs from all congeners except L. (A.) leptomyidis and L. (A.) peragale in having 6 labial lobes without interlabia. It differs from both of these species in the form of the labial lobes, shorter with truncated distal tips in L. perditus ( Fig. 19 ), longer and more triangular in shape in L. peragale ( Fig. 5 ) and shorter and rounded with small fine cuticular striations on the inner surface of the distal end of each lobe encircling the mouth opening L. leptomyidis ( Figs. 1, 2 ). The chordal lobes of the pharyngeal region of L. perditus are rectangular with a notch on the proximal surface, those of L. peragale pyramidal in shape ending proximally in a long central spine surrounded by 3–4 short spines and of L. leptomyidis are rectangular and bilobed. The radial lobes are wedge shaped in L. perditus , shorter and sharply pointed in L. peragale and L. leptomyidis . The cervical alae are smaller in L. peragale and larger in L. leptomyidis than in L. perditus . The tail of both male and female L. perditus and L. peragale is conical and blunt tipped and shorter, that of both male and female L. (A.) leptomyidis is extended into a spine like tip.

Labiobulura (Labiobulura) baylisi ( Mawson, 1960) Quentin, 1969 ( Figs 34–48 , 95 A, 98A, B, 99)

Labiobulura baylisi Mawson, 1960: 278 –280, figs 47–53 ( Isoodon macrourus (Gould) [as I. obesulus ]); Quentin, 1969: 475.

Subulura peramelis Johnston & Mawson, 1939a: 204 ( Perameles nasuta ); Johnston & Mawson 1951: 36 ( Isoodon macrourus [as I. torosus ]).

Type host. Isoodon macrourus (Gould) .

Site in host. Caecum, colon.

Material examined. Holotype male, allotype female from Isoodon macrourus Mount Nebo , Queensland, coll. M. J. Mackerras, 17. ii. 1958, SAM 41464; paratypes, 10 males, 17 females, same data SAM AHC 3285, QM GL14500.

Other material examined. From Isoodon macrourus Queensland; parts of 6 worms SAM AHC 21132, 5males, 9 females Mt Nebo, SAM AHC 19246, QM GL14494, 9 males, 5 females @ Brookfield CSIRO N143, 17males, 18 females Mount Superbus CSIRO N144: New South Wales; 2 females SAM AHC 30600, 32 males, 35 females Glenreagh CSIRO N4172, 35 males, 39 females Cascade, CSIRO N4171, 54 males, 72 females Tenterfield CSIRO N145 3 males, 7 females. From Perameles nasuta New South Wales; 2 females Gosford, SAM AHC 21128: Queensland; 1 female Innisfail SAM AHC 19764. From bandicoot Queensland; 5 males, 2 females QM GL12637.

Differential diagnosis. Labiobulura (L.) baylisi differs from all congeners except L (L.) inglisi and L. (L.) peramelis in having interlabia. It differs from both of these in the shapes of the denticles, the morphology of the labial lobes the placement of the submedian papillae, the shapes of the chordal and radial lobes of the pharyngeal portion of the oesophagus and the nuchal constriction of the cephalic end below the level of the labia.

Description. General: Robust, medium sized worms. Cuticle with annulations; cervical alae wide. Mouth opening bounded by 6 labial lobes, 4 submedians triangular in outline, each with double papilla on the mid region, 2 laterals longer, rectangular in outline, blunt proximal ends, very broad deeply curved bases, with amphids on mid region; 4 rectangular, 2 triangular interlabia, without papillae, oriented 3 dorsally, 3 ventrally; proximal end of each lateral lobe and the rectangular interlabial lobes with bilobed denticle. Buccal capsule circular in cross section, separated from pharyngeal portion by fine transverse ridge. Pharyngeal lobes cuticularized; 3 larger chordal lobes rounded, with proximal surface bifid, 3 smaller conical radial lobes, project anteriorly into buccal cavity; not extending to base of buccal capsule, chordal and radial lobes neither helical nor spiral; peripheral lobes form cup for chordal and radial lobes. Oesophagus widens gradually to terminal bulb, about 1/6.2 to 1/8.3 body length. Nerve ring surrounds anterior oesophagus; excretory pore posterior to nerve ring.

Male: Length 8–11 (9.9); width 204–340 (297). Buccal apparatus maximum dimensions 46–59.5 (59.1) long, 29.5–35.5 (32.8) wide; buccal capsule 16.5–20 long (17.8), 15.5–20 (18.7) wide. Oesophagus 1350– 1700 (1592.5) long; bulb 201–228 (217) long 181–268 (219) wide. Nerve ring 379.5– 412 (396), excretory pore 549–670 (603), from anterior end. Spicules similar, slender with longitudinal ridge, light transverse striations along one edge, proximal ends simple, distal tips pointed 1710–2560 (1860) long, about 1/5.3 body length. Gubernaculum with sides extending anteriorly, 172–214.5 (186.5) long. Tail 170–214.5 (186.5) long. Sucker pre cloacal, elongate, without cuticular elaborations 530–840 (753) from tail tip; 11 pairs caudal papillae, 3 pairs pre cloacal, 2 pairs at level of cloaca, 6 pairs post cloacal.

Female: Length 13–19 (16.2) mm; width 295–476 (372). Buccal apparatus, maximum dimensions, 46–63 (54.8) long, 33–53 (40.2) wide; buccal capsule 16.5–29.5 (21 long), 20–23 (21.9) wide. Oesophagus 1700– 2125 (1956.8) long; bulb 208–301 (240.9) long 167.5–295 (250) wide. Nerve ring 340–516 (433.5); excretory pore 502.5–782 (659.7) from anterior end. Vulva simple, unornamented, in anterior half of body, 4845–7580 (6768) from anterior end, about 1/2.4 body length. Tail elongate 556–918 (766) long, tapering to blunt tip. Eggs embryonated, thin shelled, sub globular 66–72.6 (69.3) by 53–62.7 (57.9).

Distribution and hosts. Originally described from Isoodon obesulus from southern Queensland and I. torosus and Perameles nasut a from New South Wales, L. (L.) baylisi has now been found as far north as Innisfail, Queensland and as far south as Gosford, New South Wales in P. n a s u t a as well as in localities in southern Queensland and northern New South Wales in I. macrourus . In the past the identity of the bandicoot host, I. macrourus , in this area has been misreported as I obesulus in some parasitological literature ( Mackerras & Mackerras 1960). The distribution of I obesulus , the southern brown bandicoot, extends no further north than Sydney, that of I. macrourus , the northern brown bandicoot, down coastal Queensland south to just north of Sydney ( Gordon et al. 1990; Ashby et al. 1990). Therefore records of Labiobulura species from I. obesulus from southern Queensland are in error. Moreover I. torosus , the host designation for L. baylisi as Subulura peramelis by Johnston & Mawson (1951) is a recent synonym of I. macrourus (see Gordon 2008) and therefore the type host of L. baylisi becomes I macrourus . The ‘bandicoot’ host listed from Queensland could be either of the host species, I. macrourus or P. nasuta , found in the region.

Remarks. Labiobulura (L.) baylisi differs from all congeners except L. (L.) inglisi and L. (L.) peramelis in having 6 labial lobes with interlabia. It differs from both of these species in having a nuchal constriction, giving the appearance of a knob at the anterior end. As noted by Mawson (1960) this character is independent of the position of the labial lobes, although the extent of the constriction appears influenced by the fixation history of the specimens. The shape of the labial lobes, more elongated in L. baylisi than L. inglisi and L. peramelis , the shape of the denticles, bilobed in L. baylisi , trilobed in L. inglisi and L. peramelis , the position of the papillae, near the free ends of the lobes in L. baylisi , on the bases of the lobes in L. inglisi and below the bases of the lobes in L. peramelis as well as the shape of the chordal lobes, rectangular in L. baylisi , longer, elongated, extending into the buccal cavity in L inglisi and more rounded, in L. peramelis further differentiates these species. The cervical alae are wide in L. baylisi and L. peramelis but narrow in L. inglisi .

Figures

FIGURE 94. Scanning electron micrographs of Labiobulura spp. A, L. (A.) perditus anterior end showing lateral alae; B, L. (A.) perditus posterior end male showing spicule tips and 10 of the 11 pairs labial lobes; C, L. (L.) inglisi mouth showing denticles; D, L. (L.) inglisi anterior end showing of papillae. Scale bars: A, 250 μm; B 20 μm; C, 2.2 μm; D, 50 μm.

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 18 — 33. Labiobulura (Archeobulura) perditus sp. nov. 18, anterior end male, lateral view; 19, cephalic end, en face view; 20, cephalic end, optical section lateral view; 21, cephalic end, optical section dorso-ventral view; 22, mid buccal apparatus, hand cut transverse section; 23, buccal apparatus, hand cut longitudinal section showing chordal and radial lobes; 24, spicule, proximal end; 25, vulva, lateral view; 26, alae, hand cut transverse section; 27, spicule shaft; 28, spicule tip, lateral aspect; 29, vulva, ventral view; 30, gubernaculum, ventral view; 31, Male tail, ventral view; 32, female tail, lateral view; 33, male tail, lateral view. Scale bars: 18, 32, 200 µm; 19, 20, 21, 22, 24, 26, 27, 28, 30, 25 µm; 23, 10, µm; 25, 29, 33, 50 µm; 31, 100 µm.

FIGURES 4 – 17. Labiobulura (Archeobulura) peragale Johnston & Mawson. 4, anterior end male, lateral view; 5, cephalic end, en face view; 6, cephalic end, optical section lateral view; 7, mid buccal apparatus, hand cut transverse section; 8, spicule shaft; 9, buccal apparatus, hand cut longitudinal section showing chordal and radial lobes; 10, spicule, proximal end; 11, chordal lobe, lateral aspect; 12, oesophageal bulb, lateral view; 13, vulva, lateral view; 14, female tail, lateral view; 15, male tail, lateral view; 16, spicule tip, lateral view; 17, male tail, ventral view. Scale bars: 4, 16, 100 µm; 5, 7, 8, 9, 10, 11, 13, 25 µm; 6, 50 µm; 12, 14, 17, 200 µm.

FIGURES 1 – 3. Labiobulura (Archeobulura) leptomyidis Smales. 1, cephalic end, en face view; 2, labial lobe, inner surface; 3, hand cut longitudinal section, buccal apparatus showing chordal and radial lobes. Scale bars: 1, 3 25 µm; 2, 10 µm.

FIGURES 34 — 48. Labiobulura (Labiobulur a) baylisi Mawson. 34, anterior end male, lateral view; 35, cephalic end, en face view; 36, cephalic end, optical section dorso-ventral view; 37, cephalic end, optical section lateral view; 38, mid buccal apparatus, hand cut transverse section; 39, buccal apparatus, hand cut longitudinal section showing chordal and radial lobes; 40, ala, hand cut transverse section; 41, spicule, proximal end; 42, spicule shaft; 43, spicule tips, lateral aspect; 44, vulva, lateral view; 45, gubernaculum, lateral view; 46, male tail, lateral view; 47, male tail, ventral view, 48, female tail, lateral view. Scale bars: 34, 48, 200 µm; 35, 38 – 43, 45, 25 µm; 36, 37, 44, 50 µm; 46, 47, 100 µm.