Trichuris germani, Smales, L. R., 2013

Smales, L. R., 2013, Nematodes from the caecum and colon of Pogonomys (Muridae: Anisomyini) from Papua New Guinea with the descriptions of a new genus of Oxyuridae (Nematoda: Oxyurida) and a new species of Trichuridae (Nematoda: Enoplida), Zootaxa 3599 (6), pp. 577-587 : 582-585

Trichuris germani sp. nov.

( Figs 11–24 )

Type host. Pogonomys loriae Thomas.

Site in host. Caecum.

Material examined. Holotype male, allotype female from Pogonomys loriae Munimum Village (9° 53´S 149° 23´E), Aguan area, Milne Bay Province, Papua New Guinea, coll. P. German, 19. vii. 1992 AM W.42814, W.42815; paratypes 11 males, 6 females, same data, AM W.42816.

Other material examined. From Pogonomys championi 8 males 11 females and pieces of worms ridge south of Tifalmin (5° 7´S 141° 25´E), 3 females and pieces of males and females Ofektamin (5° 5´S 141° 35´E), Milne Bay Province, AM W. 42824, W. 42825, W. 42826, W. 42827, W. 42828, W. 42829.

From Pogonomys loriae 11 males 7 females, pieces of male and female Munimum Village (9° 53´S 149° 23´E), slopes near Kawaya Village, (9° 53´S 149° 22´E), AM W. 42817, W. 42818, W. 42819, Waiep Creek Munimum Village, Aguan area, Milne Bay Province, BBM 109497A, 109443B:

From Pogonomys macrourus 3 males, piece of worm 12 k NW Tep Tep, Madang Province, BBM105049A, 105004, 1 male, 1 female NNW slopes Mount Bosavi, Southern Highlands Province BBM 103018:

From Pogonomys sylvestris 2 males, 2 females, pieces of worm 12 k NW Tep Tep, Madang Province, AM W. 42823; 2 males, 1 female, pieces of worm Margut River (9° 901´S 149° 370´E), BBM 109402A, 1 male, pieces of worms Yaiton River (9° 880´S 149° 363´E), BBM 109450, 2 males, 2 females, pieces of male and female, Munimum Village (9° 53´S 149° 32´E), 1 male, 2 females, pieces of male and female, Waibare (9° 53´S 149° 22´E), Aguan area, Milne Bay Province, AM W. 42820, W. 42821, W. 42822.

Etymology. The species is named after Pavel German who collected many of the hosts.

Description. General: large nematodes, cuticle with transverse striations. Cephalic end narrow, rounded; without stylet. Stichosome comprises single row of about 800 stichocytes.

Male: (measurements of 10 specimens) Body total length 25.2–34 (29.1) mm, width at junction of oesophagus and intestine 238–340 (261); anterior body length 13.6–18 (15.9) mm, width 119–153 (134.6); posterior body length 11.6–16 (13.2) mm, width 410–545 (483). Ratio of anterior to posterior body length 1/1.2; total body length to posterior body length 1/ 2.2 of body length. Spicule slender, distal tip rounded, 1700–3300 (2167) long. Spicule sheath spinose, sub cylindrical, slightly broader at distal end when fully extended, 490–700 (544) long. Testis with 5–6 deep convolutions, ending 2.3–3.9 (2.84) mm from posterior end. Seminal vesicle 1275–2975 (2360) long; vas deferens 1224–1530 (1364) long; cloacal tube 2000–2600 (2231) long. One pair post cloacal papillae present.

Female: (measurements of 9 specimens) Body total length 27–35 (30.2) mm, width at junction of oesophagus and intestine 150–357 (313); anterior body length 17–21 (19) mm, width 100–153 (141); posterior body length 10–14 (11.2) mm, width 527–765 (652). Ratio of anterior to posterior body length 1/1.7; total body length to posterior body length 1/ 2.7.Vulva non protrusible, 100.5–315 (208) from posterior end of oesophagus; vagina muscular, more or less looped 1140–1700 (1420) from vulva to proximal end of uterus. Anus sub terminal, 20–40 from posterior end. Eggs thick shelled, with polar plugs 42.5–63 (52.4) by 25.5–27.7 (27)

Remarks. The new species exhibits all the characteristics of the family Trichuridae, Trichurinae including body form, oesophagus having a single row of stichocytes and a well developed spicule with a spiny sheath ( Anderson & Bain, 2009). Trichuris germani sp.nov. can be distinguished from the cosmopolitan T. muris , the only other trichurid reported from murid hosts in the region, by a suite of characters including the ratio of anterior to posterior body length of males of 1.2 compared with 1.88 ( Feliu et al. 2000) and 1.85 for T. muris ( Roman 1951) , the length of the spicule 1700–3300 compared with 900–1300 ( Feliu et al. 2000) and 600–860 ( Roman 1951) for T. muris , the number of convolutions of the testis, 5–6 compared with 20 –25 for T. muris and vagina length of more than 1140–1700, allowing for looping, compared with 450–1110 ( Feliu et al. 2000) and 580–1055 ( Roman 1951) for T. muris . Comparative measurements are given in Table 3 .

All other Trichuris species found in cricetid and murid hosts have been described from Africa, T. carlieri ; North America, T. neotomae , T. opaca , T. peromysci ; South America T. arvicolae , T. laevitestis ; or the Asian part of Russia, T. petrowi and T. rhombomidis . Trichuris germani can be further distinguished from T. carlieri by having a longer spicule (1700-3300 compared with 800–850) and no vulvar appendage (Gedeolst 1916); from T. neotomae by not having a distinctly bi-lobed posterior end of the body and having smaller eggs (42.5–63 by 25.5–27.7 compared with 90 by 40) ( Chandler 1945); from T. opaca by having no ellipsoidal expansion of the extended spicular sheath, testis with 5–6 compared with 24–28 convolutions and a longer vagina (1400–1700 compared with 700–950) ( Barker 1915); from T. peromysci in having a longer spicule (1700–3300 compared with 860–1400) and smaller eggs (42.5–63 by 25.5–27.7 compared with 87–92 by 40) ( Chandler 1946); from T. arvicolae by the length of the spicule (1700–3300 compared with 730–1170), testis with 5–6 compared with 20–25 convolutions and longer vagina (1400–1700 compared with 200–700) ( Feliu et al. 2000); from T. laevitestis by having a convoluted testis, not having an expansion of the vulva and smaller eggs (42.5–63 by 25.5–27.7 compared with 80–90 by 30–40) ( Suriano & Navone 1994); from T. petrowi by not having a cephalic cuticular expansion and having eggs less than 30 wide (Skryabin et al. 1957 cited in Feliu et al. 2000); from T. rhombomidis by having a longer spicule (1700–3300 compared with 1190–1380) ( Schultz & Landa 1934).

Specimens, a male and female, of a Trichuris species were reported from Hydromys chrysogaster Geoffroy , collected from the Madang Province of Papua New Guinea ( Smales 2006c). With a spicule length of 960, a vulvar appendage and eggs 72 by 36 these specimens appear to be neither T. muris nor T. germani .

Parasite species Host Intensity Prevalence % Heterakidae

Heterakis sp. Pogonomys sylvestris 1 3.5 Oxyuridae

Pogonomicola rufala n. g. n. sp. Pogonomys loriae 1–15 14

Pogonomys sylvestris 1–2 7 Subuluridae

Subulura andersoni (Cobbold, 1887) Pogonomys championi 7 8 Trichuridae

Trichuris germani n. sp. Pogonomys championi 1–10 50

Pogonomys loriae 1–21 43

Pogonomys macrourus 1–3 16

Pogonomys sylvestris 1–5 11

Figures

FIGURES 11 – 18. Trichuris germani n. sp. Male 11. Reproductive system; 12. Oesophago-intestinal junction; 13. Spines on surface of spicule sheath; 14. Junction between seminal vesicle and vas deferens; 15. Junction between vas deferens and cloacal tube; 16. Posterior end, showing spicule and spicule sheath not extended; 17. Posterior end, showing spicule and spicule sheath extended; 18. Posterior tip, showing papillae. Abbreviations: cl = cloacal tube; int = intestine; oe = oesophagus; p = papilla; sp = spicule; sp p = spicule pouch; ss = spicule sheath; sv = seminal vesicle; vd = vas deferens. Scale bars: 11, 300 µm; 12, 17, 200 µm; 13, 25 µm; 14, 15, 16, 100 µm; 18, 50 µm.

FIGURES 19 – 24. Trichuris germani n. sp. Female 19. Anterior end; 20. Egg; 21. Vagina, lateral view; 22. Posterior end; 23. Stichosome; 24. Vulva. Abbreviations: ov = ovary; ut = uterus. Scale bars: 19, 22, 100 µm; 20, 24, 50 µm; 21, 500 µm.