Macroponema beveridgei Mawson, 1978

Sukee, Tanapan, Jabbar, Abdul & Beveridge, Ian, 2020, Revision of MaCroponema Mawson, 1978 (Nematoda: Strongylida) from macropodid marsupials with the description of two new species, Parasites & Vectors (298) 13 (1), pp. 1-21 : 5-12

Macroponema beveridgei Mawson, 1978

Type-host: Osphranter antilopinus (Gould) (Marsupialia: Macropodidae ).

Additional host: Osphranter robustus (Gould) (Marsupialia: Macropodidae ).

Type-locality: Elizabeth Downs Station via Adelaide River (13°38 ′ S, 130°29 ′ E), Northern Territory, Australia .

Type-material: Holotype ♂ ( SAM AHC 41154 ); allotype ♀ ( SAM AHC 41155 ).

Additional material examined: From Osphranter antilopinus : Northern Territory: 6 ♂♂, 4 ♀♀, Elizabeth Downs Station via Adelaide River ( SAM AHC 6083 ) ; 10 ♂♂, 10 ♀♀, Jabiluka ( SAM AHC 6418 ) ; 8 ♂♂, 3 ♀♀, Marrakai Plains , 80 km SE of Darwin ( SAM AHC 22992 ) ; 7 ♂♂, 44 ♀♀, Katherine ( SAM AHC 32701 , 34908 ) ; 1 ♀, 50 km SW of Katherine (27 A 2) (molecular voucher SAM AHC 49829 ) ; 9 ♂♂, 15 ♀♀, 8 km N of Mataranka ( SAM AHC 34913 ); Western Australia: 1 ♂, 33 ♀♀, Napier Downs Station via Derby ( SAM AHC 6304 , 45971 ) ; 2 ♀♀, Camp Creek, Mitchell Plateau ( SAM AHC 6101 ) ; Queensland: 10 ♂♂, 10 ♀♀, Burlington Station via Mount Surprise ( SAM AHC 6358 ) ; 7 ♂♂, 9 ♀♀, Mount Surprise ( SAM AHC 7246 , 25929 , 25930 ) . From Osphranter robustus woodwardi : Northern Territory: 31 ♂♂, 28 ♀♀, Katherine ( SAM AHC 25421 , 25423 , 32699 , 34870 , 34885 , 34857 ) ; 4 ♂♂, 4 ♀♀, Mount Smith ( SAM AHC 327330 ) ; 4 ♂♂, 11 ♀♀, Emerald Springs ( SAM AHC 34905 ) ; 6 ♂♂, 46 ♀♀, Willeroo Station via Katherine ( SAM AHC 34883 ) ; 7 ♂♂, 35 ♀♀, 5 km N of Mataranka ( SAM AHC 34868 ) ; 11 ♂♂, 5 ♀♀, Pine Creek ( SAM AHC 34902 ) ; 2 ♂♂, 10 ♀♀, Victoria River ( SAM AHC 34891 ) ; 2 ♀♀, Newry Station via Timber Creek ( SAM AHC 34893 ) ; Western Australia: 1 ♀, Mabel Downs Station via Kununurra ( SAM AHC 48892 ) . From Osphranter robustus erubescens (Sclater) : Queensland: 28 ♂♂, 23 ♀♀, Oban Station via Mount Isa ( SAM AHC 11654-6 ) ; 11 ♂♂, 28 ♀♀, Devoncourt Station via Cloncurry ( SAM AHC 31708 , 32518 , 32560 , 48890 ) ; 5 ♂♂, 27 ♀♀, Cloncurry ( SAM AHC 32387 , 32410 , 32420 , 32428 ) . From Osphranter robustus robustus (Gould) : Queensland: 4 ♂♂, 3 ♀♀, 24 km E of Georgetown ( SAM AHC 25425 ) : 3 ♂♂, 7 ♀♀, 17 km E of Mount Surprise ( SAM AHC 25426 ) ; 2 ♂♂, 2 ♀♀, Whitewater Station via Mount Surprise ( SAM AHC 25424 ) ; 2 ♀♀, 34 km N of The Lynd Junction ( SAM AHC 48887 ) ; 2 ♀♀, 27 km N of The Lynd Junction ( SAM AHC 48886 ) ; 1 ♂, 5 ♀♀, 8 km N of The Lynd Junction ( SAM AHC 48330 ) ; 1 ♀, Kangaroo Hills Station via Greenvale ( SAM AHC 32744 ) ; 1 ♀, Bluewater Springs ( SAM AHC 25422 ) ; 1 ♂, 2 ♀♀, Clarke River Station via Charters Towers ( SAM AHC 48888 ) ; 2 ♀♀, 74 km N of Charters Towers ( SAM AHC 48885 ) ; 2 ♀♀, 60 km N of Charters Towers ( SAM AHC 48889 ) ; 14 ♂♂, 5 ♀♀, Hillgrove Station via Charters Towers ( SAM AHC 32534 ) ; 10 ♂♂, 10 ♀♀, Fletcher View Station via Charters Towers ( SAM AHC 7411 ) ; 17♂♂, 6 ♀♀, Charters Towers ( SAM AHC 7634 , 7660 ) ; 5 ♂♂, 9 ♀♀, Warrawee Station via Charters Towers ( SAM AHC 12041 , 12320 , 25428 ) ; 54 ♂♂, 12 ♀♀, Harvest Home Station via Charters Towers ( SAM AHC 13519 , 13520 , 13521 , 15610 , 19871 , 19872 ) ; 5 ♂♂, 11 ♀♀, Prairie ( SAM AHC 32572 ) ; 10 ♂♂, 38 ♀♀, Woodbine Station via Prairie ( SAM AHC 31720 , 31724 , 32370 ) ; 13 ♂♂, 6 ♀♀, 17 km E of Jericho ( SAM AHC 31587 ) ; 1 ♂, 5 ♀♀, 50 km W of Jericho ( SAM AHC 31598 ) ; 1♀, 18 km W of Warwick ( SAM AHC 25427 ) ; New South Wales: 11 ♂♂, 14 ♀♀, Rivertree ( SAM AHC 6001 , 22991 ) ; 12 ♂♂, 10 ♀♀ Wollomombi ( SAM AHC 44350 ) .

Representative DNA sequences: Molecular voucher from O. robustus (74 km W of Cloncurry; SAM 48921 ) : GenBank : MT080016 ( ITS 1 , 5.8 S and ITS 2 ) .

Description

General. Robust, whitish nematodes. Cephalic collar absent; mouth dorso-ventrally elongate; elevation on each side of mouth opening bears lateral amphid and 2 dome-shaped sub-median papillae; papillae with 2 short, anteriorly-directed setae. Buccal capsule elongate, dorso-ventrally elongate, poorly sclerotised, with partially sclerotised annulus in mid-region of buccal capsule; buccal capsule supported externally by strong radial musculature in posterior half; non- sclerotised annulus at junction of buccal capsule with oesophagus. Oesophagus elongate; corpus cylindrical, with c. 35 sets of transverse sclerotised structures in lining, one arising from each sector of oesophagus (1 dorsal and 2 sub-ventral); isthmus short, slightly swollen; bulb elongate; intestinal cells enlarged at anterior extremity, surrounding posterior part of oesophageal bulb. Nerve-ring in anterior oesophageal region. Excretory pore at level of or posterior to oesophageal bulb; deirids at level of buccal capsule.

Male [Measurements of 10 specimens; Figs. 15–25.] Total length 15.0–20.0 (18.2); maximum width 0.63–0.94 (0.75); buccal capsule 0.13–0.18 (0.14) long, 0.10–0.12 (0.11) wide; oesophagus 3.35–4.45 (4.00); nerve-ring from anterior extremity 0.65–0.92 (0.73); excretory pore from anterior extremity 3.88–5.00 (4.33); deirid from anterior extremity 0.13–0.22 (0.18). Bursal lobes poorly separated; lateral lobes slightly longer than ventral and dorsal lobes; dorsal lobe with median indentation; ventro-ventral and ventro-lateral rays apposed, reach margin of bursa; externo-lateral ray divergent from lateral trunk, not reaching margin of bursa; medio-lateral and postero-lateral rays apposed, reaching margin of bursa; externo-dorsal ray arising from lateral trunk, stout, not reaching margin of bursa; dorsal ray slender at origin, divides at 1/3 length; branches arcuate, internal branchlets reaching margin of bursa; external branchlets very short, arise midway between principal bifurcation and tips of internal branchlets, terminate in elevations on internal surface of bursa. Spicules elongate, alate; alae with numerous, fine, transverse striations; anterior extremity irregularly knobbed; distal extremity blunt tipped; alae diminish in width gradually anterior to spicule tip, lose striations prior to termination; spicule length 1.77–2.12 (1.95); gubernaculum absent; central cordate and paired lateral thickenings of spicule sheaths present. Ventral lip of genital cone large, conical, bearing papilla 0; dorsal lip with paired bifid appendages and 2 semi-circles of digitiform projections of varying lengths.

Female [Measurements of 10 specimens; Figs. 26, 27.] Total length 40.0–62.0 (52.6); maximum width 0.85–1.15 (1.00); buccal capsule 0.13–0.22 (0.17) long, 0.12–0.17 (0.14) wide; oesophagus 4.38–5.33 (4.90); nerve-ring from anterior extremity 0.70–0.90 (0.81); excretory pore from anterior extremity 4.50–5.95 (5.35); deirid from anterior extremity 0.14–0.26 (0.19). Tail short, conical, 0.32–0.53 (0.45) long, deviated slightly dorsally; vulva 1.24–1.95 (1.52) from tip of tail; vagina short, 0.70–1.05 (0.84) long, slightly sinuous; egg ellipsoidal 0.10–0.13 (0.12) long, 0.04–0.06 (0.05) wide.

Remarks

The present re-description of M. beveridgei confirms that of Mawson [ 1] and provides additional details. The species can be readily distinguished from all congeners by its oesophageal ornamentation, with multiple transverse sclerotisations of the oesophageal lining.

Mawson [ 1] nominated Osphranter antilopinus (syn. Macropus antilopinus ) as the type-host and Elizabeth Downs Station as the type-locality. It seems likely therefore that the specimens deposited as SAM AHC 6083 from the same host and locality represent paratypes, even though they were not designated as such in the original description. Mawson [ 1] also reported the species from Notamacropus agilis (syn. Macropus agilis ) from Marrakai Plains (as Merridai Plains), but this appears to be an error. The material from this locality in SAM (SAM AHC 22992) is labelled as being from O. antilopinus . The records of this species occurring in N. agilis in Speare et al. [ 16] and in Spratt & Beveridge [ 17], based on the report by Mawson [ 1], are therefore suspect, with no supporting material from a wide range of collections from the same host species [ 16]. A further record of this species from Wallabia bicolor on Stradbroke Island, Queensland in Mawson [ 1] was again not substantiated based on collections in SAM and was not included in the parasites of this species of wallaby by Beveridge [ 18]. The validity of this record consequently needs to be confirmed.

In the present collections, M. beveridgei was most commonly encountered in O. robustus , probably because this species has been more intensely sampled than O. antilopinus . The molecular data suggest that nematodes from these two closely related macropodid species are identical. Also included in the molecular component of this study were specimens from Notamacropus dorsalis (Gray) . This association was not reported by Beveridge et al. [ 19] based on an examination of 39 N. dorsalis from Queensland. The host from which the molecular specimens were obtained was collected at the same time as a specimen of O. robustus at the same locality, and while specimens were frozen for molecular studies, it appears that none were preserved for morphological study. Assuming that there were no errors in the labelling of specimens at the time of collection, this is the first record of M. beveridgei in N. dorsalis , but it requires confirmation.

As noted by Beveridge [ 20], M. beveridgei has an unusual distribution ( Fig. 28 ), occurring across northern Australia and along the east coast as far south as north-eastern New South Wales.

Figures

Fig. 28 Distribution of Macroponema beveridgei Mawson, 1978 in Osphranter robustus and O. antilopinus in northern and eastern Australia. Closed circles represent localities at which the parasite has been collected from O.robustus; open circles indicate locations at which common wallaroos have been examined but the nematode has not been found; closed squares represent localities at which the parasite has been collected from O. antilopinus; open squares indicate locations at which antilopine wallaroos have been examined but the nematode has not been found