DOI: 10.2478/s11686-011-0067-1 © W. Stefan´ski Institute of Parasitology, PAS Acta Parasitologica, 2011, 56(4), 418–426; ISSN 1230-2821 Gastrointestinal nematodes of Coccymys ruemmleri (Rodentia, Muridae) with the description Montistrongylus giluwensis sp. nov. (Heligmonellidae) and Syphacia coccymyos sp. nov. (Oxyuridae) from Papua New Guinea Lesley R. Smales Parasitology Section, South Australian Museum, North Terrace, Adelaide, SA 5000, Australia Abstract Five species of nematode were collected from the digestive tracts of 10 Coccymys ruemmleri from Papua New Guinea. Mon- tistrongylus giluwensis sp. nov. can be distinguished from its congener by its size, in having more ridges in the synlophe, longer spicules and the form of the cuticle on the female posterior end. Syphacia (S.) coccymyos can be distinguished from all other species in the subgenus by having a laterally extended dorso-ventrally constricted oval cephalic plate and both cervical and lat- eral alae, together with the combination spicule length and egg size. The helminth assemblage had similar species richness to that of Chiruromys vates with Odilia mackerrasae the only species in common. Keywords Montistrongylus giluwensis, Syphacia coccymyos, nematode, Coccymys, murid rodent, Papua New Guinea Introduction by Musser and Lunde (2009) that C. ruemmleri also spends time in the forest understory. The rodent genus Coccymys (Muridae, Murinae) forms part To the best of my knowledge there have been neither re- of the Old Endemic lineage of murines, the earliest colonists ports of helminths nor records of parasite material in national of the Austro-Papuan, Sahul Region. It is thought to have ar- parasite collections of C. ruemmleri. As part of an ongoing rived in the region about 6–8 million years ago and diversified study of the helminths of New Guinean rodents, specimens of about 5 million years ago (Breed and Aplin 2008). Compris- C. ruemmleri stored as intact bodies in the Bishop Museum, ing two species, Coccymys albidens (Tate, 1951), known only Honolulu, Hawaii (BBM) were examined for helminths. In from the original series of six specimens and C. ruemmleri this paper helminth species are documented, new species are (Tate et Archbold, 1941), the genus has been placed in the described and comments given on the helminths found in Tribe Hydromyini (see Lecompte et al. 2008) within the Chiruromys and Hyomys, the only genera within the Pogono- Pogonomys Division (see Musser and Carleton 2005) of New mys Division for which data are available, and Lorentzimys, a Guinea murines. Coccymys ruemmleri is a montane species New Guinea Old Endemic genus with enigmatic affinities found along the Central Cordillera of New Guinea. There are (Smales 2006, 2011). no first hand observations of the biology of C. ruemmleri (see Musser and Lunde 2009). Its diet may consist only of veg- etable matter (Flannery 1995) or be similar to that of its con- Materials and methods gener Coccymys shawmayeri (Hinton, 1943) and include insects, fruit seeds and vegetation (Musser and Lunde 2009). Complete digestive tracts of 10 individuals of C. ruemmleri Known to be of partly terrestrial habit, having been found on were recovered from intact bodies collected by J.L. Gressitt, fallen logs and on the ground (Flannery 1995), it is postulated A.B. Mirza, Bin Yuo and R. Traub between 1967 and 1977 Corresponding author: [email protected] Nematodes from Coccymys ruemmleri from Papua New Guinea 419 and held at the BBM. Their fixation history was not known A male and an immature female, heligmonellids, were but they had been stored in 70% ethanol following collection found in the small intestine of a host from the southern slopes in Papua New Guinea. Collection localities, with the number of Mt Giluwe, Southern Highlands Province and could not be individuals from each, is given in parentheses. identified further. The male with a body length of 4.9 mm, Coccymys ruemmleri: Southern Highland Province; Doma width 149, oesophagus length 380, simple spicules, 792 long Peaks (1), SSE slopes of Mt Giluwe (2). Morobe Province; Mt a synlophe of about 24 small similar sized ridges midbody and Kaindi 7°21´S, 146°41´E (2), Bulldog Rd 32 km S Wau a relatively large bursa could not be placed in any presently 7°50´S, 146°43´E (1). Chimbu Province; Mt Wilhelm 5°49´S, known genus. 144°57´E (4). The digestive tracts were examined with the aid of a dis- Montistrongylus giluwensis sp. nov. (Figs 1–21) secting microscope and all helminths found were stored in 70% ethanol. Prior to examination nematodes were cleared in General: (Heligmonellidae, Nippostrongylinae). Relatively lactophenol for study as wet mounts. Transverse sections were large robust worms, body usually irregularly coiled. Cephalic prepared by hand cutting with a cataract scalpel and mounted vesicle present with up to 16 fine annulations. Mouth opening in polyvinyl lactophenol. Spicules were mounted in Berlese’s triangular with rudimentary lips; labial and cephalic papillae medium for detailed study. Figures were prepared with the aid not observed. Oesophagus claviform. Nerve ring not observed; of a drawing tube. Measurements, in micrometres unless oth- deirids, large, at about same level as excretory pore, in poste- erwise stated, and presented as the range followed by the mean rior oesophageal region. Synlophe (based on sections from 6 in parentheses, were taken with the aid of an eyepiece mi- worms) of continuous triangular longitudinal ridges in both crometer. All specimens have been returned to the BBM. sexes extends from posterior to cephalic vesicle to immedi- The adequacy of the sample size for determining the ately anterior to bursa or vulva; 14–20 ridges in anterior, 18– species richness of the helminth assemblage was tested 20 in midbody, 17–21 in posterior body; ridges absent on using the bootstrap analysis of Poulin (1998). Terminology dorsal left and lateral right sides. Axis of orientation of ridges for heligmonellid nematodes follows Durette-Desset (1983, from ventral right to dorsal left inclined at about 70° from sag- 1985) and Durette-Desset et al. (1994), for oxyurid nema- gital axis in midbody; 8–9 ridges dorsal side, 9–11 ridges todes follows Hugot (1988) and for bioregions follows Voris ventral side male; 5–8 ridges dorsal side, 8–11 ridges ventral (2000). side female. Ventral ridges slightly larger than dorsal ridges; ridges 5–9 (male), 4–8 (female) larger than 5–9 (male), 4–8 (fe- male). Axis of orientation maintained along body; lacking Results carene. Male: Body length 6.0–8.6 (6.7) mm, width 100–105 Only nematodes were collected from the digestive tracts of 7 (130). Cephalic vesicle 59.5–70 (60.8) long. Oesophageal of the 10 individuals of C. ruemmleri examined. No acantho- length 350–512 (428); deirids, excretory pore 303, 342 from cephalans, cestodes or trematodes were found. The nematode anterior end. Bursa almost symmetrical, right lobe slightly fauna included 5 species, 4 identified to species level, and is larger, pattern of rays 2–3 for both lobes; rays 2, 3 diverge dis- listed, with prevalences, in Table I. Three heligmonellids an tally, recurved ventrally; rays 4 recurved ventrally; ray 6 re- oxyurid and a spirurid were identified. Three hosts harboured curved dorsally; rays 4 more stout than rays 5, 6; rays 2, 3 2, 2 hosts, 3 and 2 hosts 1 nematode species. Using bootstrap more slender. Dorsal lobe longer than laterals, with median analysis it was estimated that the number of gastrointestinal notch; dorsal trunk bifurcates at 2/3 its length, each branch di- helminth species not found in this survey was 0.81 indicating viding again at distal tip; rays 9, 10 symmetrical, rays 8 asym- that 86% of the expected helminth species were found. All metrical, left ray 8 longer arising distally to right ray 8 from were new hosts records and for Odilia mackerrasae and Pro- dorsal trunk, both rays arise proximally to division of dorsal tospirura kaindiensis new locality records. ray. Genital come small, ventral lip with unpaired papilla 0, Table I. Nematode parasites from 10 Coccymys ruemmleri from Papua New Guinea Taxon Site in host Prevalence % Heligmonellidae Odilia mackerrasae (Mawson, 1961) small intestine 20 Montistrongylus giluwensis sp. nov. small intestine is missing 50 heligmonellid sp. small intestine 10 Oxyuridae Syphacia (Syphacia) coccymyos sp. nov. caecum 50 Spiruridae Protospirura kaindiensis (Smales, 2001) stomach 10 420 Lesley R. Smales Figs 1–13. Montistrongylus giluwensis sp. nov., male. 1. Anterior end, right lateral view showing ridges of the synlophe. 2. Genital cone, left lateral view. 3. Genital cone, dorsal view. 4. Tranverse section, anterior body. 5. Spicule tips, separated, left lateral view. 6. Spicule tips sheathed, left lateral view. 7. Spicule, proximal end. 8. Gubernaculum, left lateral view. 9. Transverse section, mid body. 10. Dorsal ray, dorsal view. 11. Transverse section, posterior body. 12. Bursa, dorsal view showing left lateral lobe. 13. Bursa, dorsal view showing right lateral lobe. Abbreviations: d – dorsal, l – left, r – right, v – ventral. Scale bars = 50 µm (1, 10), 25 µm (2–4, 7–9, 11), 10 µm (5, 6), 100 µm (12, 13) Nematodes from Coccymys ruemmleri from Papua New Guinea 421 Figs 14–21. Montistrongylus giluwensis sp. nov., female. 14. Transverse section, anterior body. 15. Anterior end, right lateral view. 16. Trans- verse section, mid body. 17. Ovejector, lateral view. 18. Vagina closed, right lateral view. 19. Transverse section, posterior body. 20. Poste- rior end, lateral view showing blunt tail tip and ventral cuticular pouch. 21. Vagina dilated, right lateral view. Abbreviations: d – dorsal, l – left, r – right, v – ventral. Scale bars = 25 µm (14, 16, 18, 19, 21), 100 µm (15, 17, 20) 422 Lesley R. Smales dorsal lip with paired papillae 7. Spicules filiform, fused at rior to oesophageal bulb.