Labiobulura (Labiobulura) inglisi ( Mawson, 1960 ) Quentin, 1969

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 : 13-16

Labiobulura (Labiobulura) inglisi ( Mawson, 1960) Quentin, 1969

( Figs 49–63 , 94 B, C, 95B, 96A–C, 98C, D, 99)

Labiobulura inglisi Mawson, 1960: 278 , 280–281, figs 54–59. ( I. obesulus [as I. nauticus ], Perameles bougainville , P. gunnii ); Quentin, 1969: 475.

Subulura peramelis Johnston & Mawson, 1939b: 309 ( P. bougainville [as P. mysosura ]).

Type host. I. obesulus (Shaw)

Site in hosts. Caecum, colon.

Material examined. Holotype male, allotype female from Isoodon obesulus, Cherry Gardens , South Australia, coll. A. Kowanko, ix. 1958, SAM 41462; paratypes 4 males, 12 females, same data, SAM AHC 3346, 21129, 21121.

Other material examined. From Isoodon obesulus South Australia; 30 males, 10 females Adelaide Hills SAM AHC 13719, 227 males, 249 females 10 larvae Cox’s Scrub Conservation Park SAM AHC 33278, 33281, 36 males, 38 females Crafers SAM AHC 8393, 8416, 105 males, 121 females Loftia Park SAM AHC 26199, 33281, 150 males, 150@ Scott Creek Conservation Park SAM AHC 33179, 33196: Tasmania; 78 males, 90 females Dunorlan SAM AHC 3317, 3343, QM GL14496, 3 males, 2 females Exeter SAM AHC 16460, 2 males, 3 females Falmouth SAM AHC 6930, 64 males, 64 females Glengarry SAM AHC 16485, 16489, 33160, 33229, 50 males, 50 females Gog Range SAM AHC 33157, 113 males, 131 females Kingston, SAM AHC 33176, 33177, 33178, 33179, 33180, 33181, 9 males, 6 females Maggs Mountain SAM AHC 16486, 15 males, 22 females Railton SAM AHC 33156, 1 male, 2 females Stanley SAM AHC 5375, 5376, 5377, 15 males, 11 females Upper Dromedary SAM AHC 23002: Victoria; 4 males, 8 females Anglesea SAM AHC 44310, 38 males, 70 females Healesville SAM AHC 4895, 33273, 33289, 33 males, 48 females Portland SAM AHC 33246, 33248, 11 males, 30 females no other data SAM AHC 33247: Western Australia; 45 males, 90 females Glen Forest WAM V57, 60, 211 males, 226 females 5 larvae Perth SAM AHC 8893, 8895, 33225, 33226, 33227, 33228, 33229, 33230, 33235, 33238, 33240, WAM V3984, 40 males 40 females Murdoch University SAM AHC 8902. From I. o. nauticus Nuyts Archipelago; 55 males, 56 females Franklin Island CSIRO N2814 SAM AHC 4781, 46 males, 107 females Saint Francis Island SAM AHC 33142, 33143, 254 males, 317 females 20 larvae West Franklin Island SAM AHC 6354, 33141, 33144, 33145, 33146, 33147, 33148, 33149, 56 males, 85 females no locality data SAM AHC 2929, 21127. From Perameles bougainville Western Australia; 2 males, 13 females Dorre Island SAM AHC 44697 91 males, 126 females Kanyana Wildlife Research Centre SAM AHC 44698, 44696, 44699, 44700. From Perameles gunnii Ta smania; 62 males, 61 females Kingston SAM AHC 33166, 33167, 33169, 33173, 5 males, 19 females Smithton SAM AHC 5370, 5371, 5372, 5373, 243 males, 300 females Stanley SAM AHC 5328, 4329, 5330, 5331, 5332, 5333, 5334, 5335, 5336, 5337, 5338, 5339, 5340, 5341, 5342, 5343, 5344, 5345, 5346, 5347, 5348, 5349, 5350, 5351, 5352, 5353, 5357, 17856, 8 males, 11 females Wiltshire Junction SAM AHC 5360, 5362, 5363, 5365, 1 female no locality CSIRO N1800. From bandicoot Western Australia; 1 male, 1 female Glen Forest SAM AHC 44702, 44703; Victoria; 2 females Molesworth SAM AHC 16491.

Differential diagnosis. Labiobulura (L.) inglisi differs from all congeners except L. (L.) baylisi and L. (L.) peramelis in having interlabia. It differs from both of these in the morphology of the labial lobes, the shape of the denticles, the placement of the submedian papillae, the proportions of the buccal apparatus, 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 narrow. Mouth opening bounded by 6 labial lobes, 4 submedians triangular in outline, each with double papilla on base, 2 laterals longer, more rectangular in outline, blunt proximal ends, broader slightly rounded bases with amphids; 4 rectangular, 2 triangular interlabia, without papillae, oriented 3 dorsally, 3 ventrally; proximal end of each lateral lobe and the rectangular interlabial lobes with quadri lobed denticle. Buccal capsule circular in cross section, separated from pharyngeal portion by fine transverse ridge, pharyngeal portion of the buccal apparatus elongated. Pharyngeal lobes cuticularized; 3 larger chordal lobes elongated, may project anteriorly into buccal cavity; 3 smaller conical radial lobes, 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 1/5.7 to 1/8.5 body length. Nerve ring surrounds anterior oesophagus; excretory pore posterior to nerve ring.

Male: Measurements of worms from I. obesulus from South Australian localities. Length 8–10 (8); width 225–323 (280). Buccal apparatus maximum dimensions 68–100 (77.7) long, 19.8–42.5 (33.5) wide; buccal capsule 23.1–29.7 (25.4) long, 13.2–19.8 (16.8) wide. Oesophagus 1139–1650 (1395) long; bulb 178–254 (219) long 162–228 (195) wide. Nerve ring 330–380 (355), excretory pore 422–703 (573), from anterior end. Spicules similar, slender with longitudinal ridge, faint transverse striations along one edge, proximal ends simple, distal tips pointed 1200–2320 (1703.5) long, about 1/4.7 body length. Gubernaculum with sides extending anteriorly, 132–175 (155) long. Tail 152–181.5 (170.4) long. Sucker pre cloacal, elongate, without cuticular elaborations 450–700 (608) from tail tip; 11 pairs caudal papillae, 3 pairs pre cloacal, 2 pairs at level of cloaca, 6 pairs post cloacal.

Female: Measurements of worms from I. obesulus from South Australian localities. Length 10–16 (13.5) mm; width 272–357 (320). Buccal apparatus, maximum dimensions, 82.5–100.3 (89.4) long, 27.2–42.5 (37.7) wide; buccal capsule 29.7–33 (31.2) long, 16.5–23.1 (18.3) wide. Oesophagus 1275–189 (1592) long; bulb 221–255 (237.9) long 167.5–235 (209.9) wide. Nerve ring 335–415 (398); excretory pore 522–650 (560) from anterior end. Vulva simple, unornamented, in anterior half of body, 3706–4930 (4580) from anterior end, about 1/3 body length. Tail elongate 884–1156 (976.5) long, tapering to blunt tip. Eggs embryonated, thin shelled, sub globular 49.5–62.7 (55) by 46.2–52.8 (48.4).

Larvae: Length 650–1700 (1550), width 63–100 (86.5). Oesophagus 100–500 (322) long; nerve ring 142–214 (167), excretory pore 264 (1 measurement) from anterior end. Tail 80–182 (115) long.

Distribution and hosts. Labiobulura (L.) inglisi is widely distributed across southern Australia wherever bandicoots have been sampled. First reported from Isoodon obesulus obesulus from South Australia and I. o. affinus from Tasmania as I. obesulus , I. o. nauticus as I. nauticus from the Nuyts Archipelago, Perameles gunnii and P. bougainville as P. myosura from Western Australia L. inglisi is now also recorded from I. o. fusciventer from Western Australia. Johnston & Mawson (1939b) when noting their finding of L. inglisi in P. bougainville from Western Australia did not record the locality where the host was collected. The names and spelling they used for the host, P. mysosura , (see Johnston & Mawson 1939b) and P. bougainvillei (sic) (see Mawson, 1960) suggest that the host animal may have been collected from the plains near the head of the St Vincent Gulf, South Australia because these spellings were used by Thomas for hosts collected from that locality ( Mahoney & Ride 1988). More recent collections (this study) have included an infected host from Dorre Island in Shark Bay and hosts that had been relocated to a wildlife refuge on the Western Australian mainland.

Remarks. Labiobulura (L.) inglisi differs from all congeners in having quadri lobed denticles and all except L. (L.) baylisi and L. (L.) peramelis in having 6 labial lobes with interlabia. It differs from L. baylisi in having a longer buccal apparatus, 68–100 in males compared with 46–59.5, not having a nuchal constriction of the anterior end and having papillae on the base of the labial lobes not on the mid region. Labiobulura inglisi differs from L. peramelis in having a more narrow buccal apparatus, 19–42.5 compared with 34–92.5 in males, broader lateral lobes with rounded bases and in the position of the papillae, below the bases of the lobes in L. peramelis . The shape of the chordal lobes, longer, elongated, extending into the buccal cavity in L inglisi and shorter, rectangular in L baylisi , and L. peramelis further differentiates these species. The cervical alae are narrow in L inglisi and wider in L baylisi , and L. peramelis .

Although there are some differences in the range of measurements of worms taken from hosts in different localities (see the table of comparative measurements in Mawson 1960) they appear to represent slight differences due to either the maturity of the worms, the effects of the host species and or the effects of differing fixation schedules rather than specific differences between populations.

The larvae observed in some collections from South Australia and the Nuyts Archipelago showed neither developing genital apparatus, sexual differentiation at the posterior end nor fully developed cephalic region and were consequently thought to be developing third stage larvae.

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.

FIGURES 49 – 63. Labiobulura (Labiobulura) inglisi Mawson. 49, anterior end male, lateral view; 50, cephalic end, en face view; 51, cephalic end, optical section dorso-ventral view; 52, cephalic end, optical section lateral view; 53, mid buccal apparatus, hand cut transverse section; 54, spicule tip lateral aspect; 55, spicule shaft; 56, buccal apparatus, hand cut longitudinal section showing chordal and radial lobes; 57, vulva, lateral view; 58, ala, hand cut transverse section; 59, spicule, proximal end; 60, gubernaculum, lateral view; 61, male tail, lateral view; 62, male tail, ventral view, 63, female tail, lateral view. Scale bars: 49, 63, 200 µm; 50 – 56, 58 – 60, 25 µm; 57, 61, 50 µm; 62, 100 µm.