Macroponema arundeli Beveridge, 2020

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 : 4-5

Macroponema arundeli Beveridge n. sp.

Type-host: Macropus giganteus Shaw (Marsupialia: Macropodidae ).

Type-locality: 53 km N of The Lynd Junction (18°53 ′ S, 144°33 ′ E), Queensland, Australia .

Type-material: Holotype ♂ ( SAM AHC 48933 ); allotype ♀ ( SAM AHC 48934 ); 24 paratypes: 4 ♂♂ and 20 ♀♀ ( SAM AHC 48935 ).

Additional material examined: Queensland: 2 ♂♂, 3 ♀♀, 53 km N of The Lynd Junction ( SAM AHC 48907 , 48909 ) ; 1 ♂, 5 ♀♀, 29 km N of The Lynd Junction ( SAM AHC 48898 ) ; 1 ♂, 5♀♀, The Lynd Junction ( SAM AHC 48897 ) ; 1♀, Bluewater Springs ( SAM AHC 48908 ) ; 1 ♂, Woodstock ( SAM AHC 48911 ) ; 4 ♂♂, 8 ♀♀, Landsdown Station via Woodstock ( SAM AHC 48911 ) ; 1 ♀, 5 km S of Reid River ( SAM AHC 32758 ) ; 1 ♂, 10 ♀♀, Mingela ( SAM AHC 23231 , 48910 ) ; 4 ♂♂, 17 ♀♀, Harvest Home Station via Charters Towers ( SAM AHC 48896 , 48901 , 48913 ) ; 2 ♂♂, 12 ♀♀, Pallamana Station via Charters Towers ( SAM AHC 48912 , 48954 ) ; 6 ♂♂, 9 ♀♀, Homestead ( SAM AHC 48894 ) ; 1 ♀, Prairie ( SAM AHC 32592 ) ; 1 ♂, 6 km W of Prairie ( SAM AHC 48904 ) ; 1 ♀, 14 km N of Clermont ( SAM AHC 48900 ) ; 5 ♂♂, Inkerman Station via Home Hill ( SAM AHC 48903 ) ; 1 ♂, 1 ♀, Yaamba ( SAM AHC 12053 ) ; 6 ♂♂, 35 ♀♀, 66 km N of Rockhampton ( SAM AHC 48895 ) ; 3 ♂♂, 1 ♀, 40 km N of Rockhampton ( SAM AHC 48902 ) ; 2 ♂♂, 9 ♀♀, Rockhampton ( SAM AHC 48916 ) ; 1 ♂, Darling Plains Station via Banana ( SAM AHC 46096 ) ; 1 ♀, 3 km N of Miles ( SAM AHC 23231 ) ; 1 ♂, 4 km east of Oman Ama ( SAM AHC 48899 ) ; 3 ♂♂, 4 ♀♀, Killarney ( SAM AHC 48914 ) ; New South Wales: 1 ♂, 1 ♀, Kingstown ( SAM AHC 48915 ) .

Representative DNA sequences: Molecular voucher from M. giganteus (Prairie; SAM 48922 ) : GenBank : MT080011 ( ITS 1 , 5.8 S and ITS 2 ) .

Etymology: Named after Dr J. H. Arundel, who first collected the specimens upon which the description of M. comani and the genus was based.

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 anterior half; buccal capsule supported externally by strong radial musculature in posterior half; sclerotised annulus at junction of buccal capsule with oesophagus. Oesophagus elongate; corpus widest at level of and posterior to nerve-ring; posterior half of corpus with arcuate sclerotised thickenings in lining, one arising from each sector of oesophagus; isthmus narrow, elongate; bulb elongate; intestinal cells enlarged at anterior extremity, not 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. 2–11.] Total length 19.0–25.0 (21.7); maximum width 0.62–0.90 (0.74); buccal capsule 0.15–0.18 (0.17) long, 0.09–0.11 (0.10) wide; oesophagus 3.60–4.45 (4.13); nerve-ring from anterior extremity 0.83–1.05 (0.88); excretory pore from anterior extremity 3.50–4.68 (3.98); deirid from anterior extremity 0.11–0.14 (0.12). 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 1/4 length; branches arcuate, internal branchlets elongate, reaching margin of bursa; external branchlets very short, arising at middle 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 towards spicule tip, lose striations prior to termination; spicule length 1.95–2.40 (2.14); 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.

Female [Measurements of 10 specimens; Figs. 12, 13.] Total length 37.0–70.0 (49.6); maximum width 0.85–1.40 (1.13); buccal capsule 0.18–0.25 (0.20) long, 0.10–0.15 (0.12) wide; oesophagus 4.95–6.00 (5.47); nerve-ring from anterior extremity 0.93–1.25 (1.06); excretory pore from anterior extremity 4.68–6.25 (4.96); deirid from anterior extremity 0.09–0.17 (0.12). Tail short, conical, 0.38–0.53 (0.46) long, deviated slightly dorsally; vulva 1.05–1.53 (1.27) from tip of tail; vagina short, 0.90–1.30 (0.78) long, straight; eggs not seen.

Remarks

Macroponema arundeli n. sp. is readily distinguishable from congeners based on the ornamentation of the oesophagus, with a unique arrangement of arcuate sclerotised formations in each dorsal and two subventral sectors of the oesophagus. This species was found only in Ma. giganteus in north-eastern New South Wales and Queensland ( Fig. 14 ) and commonly co-occurred with M. comani . The new species can be readily distinguished from M. comani by its larger size, the pattern of oesophageal ornamentation, the termination of the spicular ala (abrupt in M. comani ; gradual in the new species) and the fact that the enlarged anterior intestinal cells do not envelope the posterior region of the oesophageal bulb, as is the case in M. comani .

Figures

Fig. 14 Distribution of Macroponema arundeli n. sp. from Macropus giganteus in eastern Australia. Closed circles represent localities at which the parasite has been collected; open circles indicate locations at which kangaroos have been examined but the nematode has not been found.The stippled area indicates the known geographical range of M.giganteus