Syphacia (Syphacia)

Weaver, H. J. & Smales, L. R., 2008, New species of Syphacia (Syphacia) Seurat (Nematoda: Oxyuridae) from Pseudomys species (Rodentia: Muridae) from central Australia, Zootaxa 1775 (1), pp. 39-50 : 45

Syphacia (Syphacia) sp. 3

( Figs 21–22 )

Material examined. From the caecum of Pseudomys hermannsburgensis Ethabuka Station , Queensland (23 o 52.28’S, 138 o 28.49’E), July 2000, 12 females, AHC 34475 , Mt. Leonard Station , Queensland (25 o 42’S, 140 o 37’E), 12.iv.1984, 18 females, AHC 34474 .

Description. Female: Small nematodes, cuticle with faint striations. Cephalic plate oval, constricted dorsally and ventrally between mouth opening and level of amphids and cephalic papillae which are close together laterally, not on edge of plate ( Fig. 19 ). Mouth opening with 3 lips. Deirids not seen. Small cervical alae present, lateral alae absent. Length 1900–3450. Maximum width 148–193. Amphids 50 apart. Oesophagus length 195–300. Oesophageal bulb 73–85 in diameter. Nerve ring 95–140, excretory pore 225–420, vulva protruding through body wall, 420–733 from anterior. Tail 313–500 long. Eggs 105–127 long, 23–35 wide.

Remarks. As discussed for the species described above, Syphacia sp. 3 belongs in the subgenus Syphacia Seurat, 1916 . The females of Syphacia sp. 3 can be distinguished from all other females in the group of Syphacia spp. with similarly shaped oval cephalic plates, namely S. (S.) abertoni , S. (S.) brevicaudata , S. (S.) pseudomyos and Syphacia sp. 2 , and all other species of Syphacia occurring in the region in having the vulva protruding through the body wall. The only other known species of Syphacia with this trait are S. (S.) ohtaorum Hasegawa, 1991 with a laterally stretched cephalic plate and S. (S.) evaginata Hugot & Quentin, 1985 with an oval cephalic plate ( Hasegawa 1991; Hugot & Quentin 1985). Syphacia sp. 3 further differs from S. (S.) ohtaorum in having cervical alae and smaller eggs (105–127 by 23–35 compared with 128–139 by 34–40) ( Hasegawa 1991). Syphacia sp. 3 has neither the prominent deirids nor the lateral alae found in S. (S.) evaginata and larger eggs (105–127 by 23–35 compared with 75 by 30) ( Hugot & Quentin 1985). Syphacia (Syphacia) sp. 3 appears to be sufficiently different from other known species, but this cannot be confirmed with a small sample size and more material, particularly males, will need to be collected.

Figures

FIGURES 17–22. 17. Syphacia sp. 1 anterior end, lateral view. 18. Syphacia sp. 1 en face view. 19. Syphacia sp. 1, en face view. 20. Syphacia sp. 1 Egg, lateral view. 21. Syphacia sp. 2 en face view. 22. Syphacia sp. 2 mid-body, lateral view. Scale bars: 18, 19, 21 = 25µm; 17, 20 = 50µm; 22 = 100µm.