Syphacia (Syphacia) pseudomyos, Weaver & Smales, 2008

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 : 43-44

publication ID 10.11646/zootaxa.1775.1.3

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scientific name

Syphacia (Syphacia) pseudomyos

sp. nov.

Syphacia (Syphacia) pseudomyos   sp. nov.

( Figs 9–16 View FIGURES 9–16 )

Material examined. Holotype: male from caecum, Pseudomys hermannsburgensis, Ethabuka   Station , Queensland, Australia (23 o 52’S, 138 o 28’E), ix–x.1991, SAM AHC 34466 View Materials . GoogleMaps  

Allotype: female, same data, SAM AHC 34467 View Materials .  

Paratypes: 3 male and 55 female, same data, SAM AHC 34468 View Materials   .

Other Material examined. From P. hermannsburgensis, Ethabuka   Station, Queensland, Australia (23 o 46’S, 138 o 29’E), 3.viii.2000, 3 males and 22 female SAM AHC 34469 View Materials GoogleMaps   .

Description. General: Small nematodes, cuticle with faint transverse striations. Cephalic plate oval, constricted dorsally and ventrally between mouth opening and level of amphids and cephalic papillae which are close to each other laterally ( Fig. 12 View FIGURES 9–16 ). Mouth opening surrounded by 3 lips. Deirids not seen. Cervical and lateral alae absent.

Male: Length 938–1175 (n=7, =1042.9, sd=84.5). Maximum width 92.5–102.5 (n=7, =94.3, sd=8.9). Amphids 25 apart. Oesophagus length 140–175 (n=7, =151.1, sd=11.7). Oesophageal bulb 53 (n=1) long, 42.5–65 (n=7, = 50.7, sd=7.0) wide. Nerve ring 57.5–82.5 (n=7. = 71.2, sd= 10.5), excretory pore 192.5– 230 (n=7, =212.1, sd=16.3), anterior mamelon 150–265 (n=7, =237.9, sd=39.6) from cephalic extremity. Mamelons, 3, oval shaped, anterior mamelon 37.5–52.5 (n=7, =46.1, sd=6.3), middle mamelon 32.5–55 (n=7, =43.9, sd=7.2), posterior mamelon 37.5–60 (n=7, =47.8, sd=7.8) long. Spicule sharply pointed, 55– 65 (n=7, =60, sd=5.6) long. Gubernaculum 27.5–40 (n=7, =33.6, sd=4.8) without obvious ornamentation. Caudal alae present; 2 pairs cloacal, 1 pair large post-anal papillae. Tail 80–175 (n=7, =103.3, sd=35.9) long, whip structure 66–130 (n=2) long.

Female: Length 2190–3050 (n=20, = 2365.9, sd=298.9). Maximum width 140–182.5 (n=20, =142.9, sd=16.55). Amphids 32 apart. Oesophagus length 232.5–275 (n=20, =233, sd=22.8). Oesophageal bulb 69 (n=1) long, 65–77.5 (n=20, =67.1, sd=5.6) wide. Nerve ring 90–142.5 (n=20, =114.6, sd=31.7), excretory pore 282.5–412.5 (n=20, =313.6, sd=35.8), vulva 502.5–775 (n=20, =528.8, sd=108.7) from anterior. Tail 250–475 (n=20, =290.9, sd=69.3) long. Eggs 107.5–125 (n=10, =115, sd=6.6) long, 32.5–37.5 (n=10,

=35.8, sd=6.6) wide.

Etymology. Named after the generic name of the host rodents, Pseudomys   .

Remarks. For the same reasons as discussed above for S. (S.) brevicaudata   , this new species belongs in the genus Syphacia   and subgenus Syphacia Seurat, 1916   . Similarly Syphacia (Syphacia) pseudomyos   sp. nov. is closest to Group V as defined by Quentin (1971) and Hugot (1988; 2005) as listed above. Syphacia (S.) pseudomyos   is most similar to S. (S.) abertoni   and S. (S.) brevicaudata   in having a constricted cephalic plate but differs from S. (S.) abertoni   , in not having cervical alae, having the excretory pore and first mamelon in more anterior positions and larger eggs (Table 2) and from S. (S.) brevicaudata   in having only one pair of post anal papillae.

There are three congeners in the Australian bioregion with an oval cephalic plate that is not dorso-ventrally constricted, namely S. (S.) darwini   , S. (S.) longaecauda   and S. (S.) sulawesiensis   that can be further distinguished from S. (S.) pseudomyos   in having only two mamelons, S. (S.) darwini   , or a longer tail (370–490 compared with 80–175 in males), S. (S.) longaecauda   , or a shorter spicule (55–65 compared with 78–89), S. (S.) sulawesiensis ( Hasegawa & Tarore 1996)   . Syphacia (S.) australasiensis   and S. (S.) muris   with quadrangular cephalic plates further differ from S. (S.) pseudomyos   in having a shorter tail (80–175 compared with 142–181 and 170–285 respectively in males) and larger eggs (107.5–125 by 32.5–37.5 compared with 82–95 by 29–36 and 76–88 by 24–32 respectively) (Table 2; Hasegawa & Tarore 1996; Smales 2004).


South African Museum