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 : 44-45

Syphacia (Syphacia) sp. 2

( Figs 19–20 )

Material examined. From the caecum of Pseudomys hermannsburgensis, Bladensburg National Park , Queensland (22 o 30’S, 143 o 02’E), 13.iii.2001, 6 females AHC 34472 ; Ethabuka Station , Queensland (23 o 48.79’S, 138 o 03.62’E), August 1999, 7 females AHC 34473 ; Nappa Merrie Station , Queensland (27 o 23’S, 141 o 20’E), 21.viii.1975, 3 females AHC 34471 ; Nockatunga Station , Queensland (27 o 43’S, 142 o 43’E), 18.vii.1976, 45 females, AHC 34470 .

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. 17 ). Mouth opening surrounded by 3 lips. Deirids not seen. Small cervical alae present, lateral alae absent. Length 1480–3580. Maximum width 130–215. Amphids 34 apart. Oesophagus length 158–245. Oesophageal bulb 60–85 in diameter. Nerve ring 85–163, excretory pore 205– 388, vulva 332–672 from anterior. Tail 200–473 long. Eggs 85–123 long, 28–38 wide.

Remarks. For the same reasons as discussed above for S. (S.) brevicaudata and S. (S.) pseudomyos , these females belong in the subgenus Syphacia Seurat, 1916 . The females of Syphacia sp. 2 can be distinguished from that group of Syphacia spp. which also have oval cephalic plates, dorsally and ventrally constricted between the mouth opening and the laterally positioned amphids and cephalic papillae as follows: from S. (S.) brevicaudata , and S. (S.) pseudomyos by the presence of cervical alae and from S. (S.) abertoni by having larger eggs (Table 2). Of the other species occurring in the region the presence of cervical alae distinguishes Syphacia sp. 2 from S. (S.) australasiensis and S. (S.) muris , which both have quadrangular shaped cephalic plates and no cervical alae. Whereas S. (S.) darwini , S. (S.) longaecauda and S. (S.) sulawesiensis , which have oval cephalic plates and lateral alae, can be further distinguished by longer tails, 200–473 compared with 700, 616–850 and 544–670 respectively ( Quentin 1971; Hugot & Quentin 1985; Hasegawa & Tarore 1996; Smales 2001; 2004). Syphacia (Syphacia) sp. 2 appears to be sufficiently different to other species to be considered a separate species, but in the absence of male specimens, and given the small sample size, more data will need to be collected to confirm this.

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.