Labiobulura (Archeobulura) peragale ( Johnston & Mawson 1940 ) 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 : 6-8

Labiobulura (Archeobulura) peragale ( Johnston & Mawson 1940) Quentin, 1969

( Figs 4–17 , 99 )

Subulura peragale Johnston & Mawson, 1940: 472 –473, figs 22–24 ( Macrotis leucura (Thomas) [as Peragale minor ]); Labiobulura peragale Inglis, 1958: 595, 1960: 129 ; Mawson 1960: 279 ( Macrotis leucura [as Thalacomys minor ]); Labiobulura (Archeobulura) peragale Quentin, 1969: 474 ( Macrotis [as Thalacomys ]); Smales 2006: 65 ( Macrotis

leucura ).

Type host. Macrotis leucura (Thomas) .

Site in host. Stomach?

Material examined. Holotype male, allotype female from Macrotis leucura, MacDonald Downs , central Australia, coll. T.H. Johnston, SAM AHC 42176; paratypes 1 male, 1 female, AHC 42674.

Other material examined. From Macrotis leucura Central Australia: 1 male, MacDonald Downs, SAM AHC 22126, anterior ends of 7 worms.

Differential diagnosis. Distinguished from all congeners except L. leptomyidis by the lack of interlabia and from L. leptomyidis by the lack of striations on the labial lobes, the shape of the labial lobes surrounding the mouth opening and the shapes of the chordal and radial lobes of the pharyngeal portion of the oesophagus, the size of the cervical alae and the shape of the female tail.

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 each with double papilla, 2 laterals each with amphid at base of lobes. Buccal capsule circular in cross section, separated from pharyngeal portion by fine transverse ridge. Pharyngeal lobes cuticularized; 3 larger chordal lobes wide at base, ending with 3, 4 short spines grouped around base of single long spine, project anteriorly into buccal cavity; 3 radial lobes shorter, blunt, 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, about 1/7 to 1/8 body length. Nerve ring surrounds anterior oesophagus; excretory pore posterior to nerve ring.

Male: Measurements of 2 specimens followed by measurements, where given, from Johnston & Mawson (1940). Length 7.5,11; 9–10.6; width 335. Buccal apparatus maximum dimensions 35 long, 40 wide; buccal capsule 15 long, 20.5 wide. Oesophagus 1440; 1060 long; bulb 218,185; 200 wide. Nerve ring 435; 400, excretory pore not seen; 550, from anterior end. Spicules similar, slender with longitudinal ridge, transverse striations along one edge, proximal ends simple, distal tips pointed 2000, 2200; 2900 long, about 1/4 body length. Gubernaculum with sides extending anteriorly 145, 190 long. Tail 174, 260 long. Sucker pre cloacal, elongate, without cuticular elaborations; 11 pairs caudal papillae, 3 pairs pre cloacal, 2 pairs at level of cloaca, 6 pairs post cloacal.

Female: Measurement of 1 specimen, followed by measurements, where given, from Johnston & Mawson (1940). Length 17; 13–15 mm; width 425. Buccal apparatus, maximum dimensions, 50 long, 60 wide; buccal capsule, 23 long, 30 wide. Oesophagus 1700; 1950 long; bulb 210, long, 220 wide. Nerve ring 420, excretory pore, 603 from anterior end. Vulva simple, unornamented, in anterior half of body 5388; 5000 from anterior end, about 1/2.9 body length. Tail elongate 697; 800 long, tapering to blunt tip. Eggs embryonated, thin shelled, sub globular 60 by 40; 60–70 in diameter.

Distribution and host. Labiobulura (A.) peragale is known from a single collection from a locality in central Australia. The host, Macrotis leucrura , is assumed to have become extinct in the 1960’s ( Johnson, 2008a) therefore no further collecting from the type host is possible. There are no records of any species of Labiobulura from the only other extant thylacomid host, Macrotis lagotis (Reid) . Given that the conservation status of M. lagotis is vulnerable ( Johnson, 2008b) the potential for finding more specimens of L. peragale , or any related species is limited.

Remarks. Although only a small number of specimens have ever been examined the distinguishing features of the anterior end and shape of the female tail clearly separate L. (A.) peragale from its congeners as discussed above. No differences in morphology or morphometrics were found between the description given by Johnston & Mawson (1940) and in this study, thus confirming the validity of the species.

The site of infection of L. peragale is given as the stomach ( Johnston & Mawson, 1940) although all other species in the genus are found in the lower small intestine, caecum and/ or colon. It seems most likely that L. peragale normally occurs in those same sites and that the reported site of infection was the result of confusion during the collection and dissection processes.

Figures

FIGURE 99. Distributions of bandicoots, Isoodon and Perameles species, across Australia. Closed squares represent general localities where Labiobulura species have been collected.

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.