Syphacia sp.

Panti-May, Jesús Alonso, Moguel-Chin, Wilson Isaias, Hernández-Mena, David Iván, Cárdenas-Vargas, Miguel Humberto, Torres-Castro, Marco, García-Prieto, Luis, Digiani, Maria Celina, Hernández-Betancourt, Silvia F. & Vidal-Martínez, Víctor Manuel, 2023, Helminths of small rodents (Heteromyidae and Cricetidae) in the Yucatan Peninsula, Mexico: an integrative taxonomic approach to their inventory, Zootaxa 5357 (2), pp. 205-240 : 224

Syphacia sp. (3)

Site of infection: Caecum and large intestine

Host species: Ototylomys phyllotis

Localities: Hobonil ranch, Vallazoo, and Kuncheil cattle ranch (Yucatan)

Specimens deposited: 12031‒12033

Comments: We found only two males, but they were in poor condition to characterize and compare them with their congeners. Female specimens had a cuticle with fine transverse striations; a cephalic plate round ( Figure 5J ); esophageal isthmus present; deirids absent ( Figure 5K ); cervical alae absent; lateral alae absent but two folds occurs at the position where the former would be ( Figure 5L ), beginning at level of nerve ring extending posterior to the anus; body 3500–3630 long; tail 470 long; vulva not prominent; and eggs 58 long by 26 wide ( Figure 5M ). The presence of two lateral folds is a feature shared only with Sy. phyllotios , parasite of Phyllotis darwini in Chile. However, this species has several characteristics that differentiate it from our specimens, such as a cephalic plate laterally elongated, presence of deirids, and vulva slightly prominent. The characteristics exhibited by our specimens clearly distinguish them from the other Syphacia found in New World rodents. These specimens likely represent a new, undescribed Syphacia species, however, new material, mainly males, should be collected to describe this species.

In Yucatan, Sy. obvelata was reported from O. phyllotis by Chitwood (1938). However, this record was based on an immature female and no morphological description was provided. This study extends the geographical range of the genus Syphacia to Quintana Roo.

Figures

FIGURE 5. A. SEM micrograph of cephalic plate of female Syphacia peromysci from Peromyscus yucatanicus, apical view. B. SEM micrograph of anterior extremity of female Syphacia peromysci from Peromyscus yucatanicus showing the cervical alae (arrow), ventral view. C. SEM micrograph of complete male of Syphacia peromysci from Peromyscus yucatanicus showing the mamelons (arrows), lateral view. D. Caudal extremity of male Syphacia peromysci from Peromyscus yucatancus showing the caudal papillae (arrows), lateral view. E. Egg of Syphacia peromysci from Peromyscus yucatanicus, lateral view. F. Cephalic plate of female Syphacia sp. (1) from Heteromys gaumeri, apical view. G. Egg of Syphacia sp. (1) from Heteromys gaumeri, lateral view. Cephalic plate of female Syphacia sp. (2) from Reithrodontomys gracilis showing the cervical alae (arrow), apical view. I. Egg of Syphacia sp. (2) from Reithrodontomys gracilis, lateral view. J. SEM micrograph of cephalic plate of female Syphacia sp. (3) from Ototylomys phyllotis, apical view. K. Anterior extremity of female Syphacia sp. (3) from Ototylomys phyllotis showing the isthmus (arrow), ventral view. L. SEM micrograph of anterior extremity of Syphacia sp. (3) from Ototylomys phyllotis showing the lateral folds (arrow), lateral view. M. Egg of Syphacia sp. (3) from Ototylomys phyllotis, lateral view. N. SEM micrograph of the anterior section of female Syphacia sp. (4) from Ototylomys phyllotis showing the cuticle with transverse striations and shallow longitudinal depressions, lateral view. O. SEM micrograph of cephalic plate of female Syphacia sp. (4) from Ototylomys phyllotis, apical view. P. Anterior extremity of female Syphacia sp. (4) from Ototylomys phyllotis showing the deirids (arrow), ventral view.