Monodontus 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 : 216-217

Monodontus sp.

Site of infection: Small intestine

Host species: Sigmodon toltecus

Locality: Ich ha lol xaan ecological park and Balam Nah eco-hotel (Campeche)

Specimens deposited: CNHE 11990

GenBank accession number: OR271661

Comments: Infected rodents harbored only females. The characteristics of the mouth, i.e., buccal capsule well developed with two semilunar ventral cutting plates at oral margin ( Figure 4B ), a dorsal tooth terminating the dorsal gutter, two irregular subventral teeth, and irregular toothlike serrations on lateral ridge, ventral teeth absent and dorsal inclination of anterior extremity pronounced, allows us to place the specimens in the genus Monodontus ( Chitwood & Jordan 1965). The main measurements of our specimens were: body 5290‒5560 long and 315‒350 wide; esophagus 570‒575 long; cervical papillae 250‒365 from the anterior end; vulva 2430‒2563 from the anterior end; and eggs 50‒65 long by 30‒40 wide. However, more specimens, particularly males, are necessary to identify this taxon at the species level.

This is the first record of Monodontus in Mexico.

Figures

FIGURE 4. A. Posterior end of male specimen of Trichuris silviae from Heteromys gaumeri showing the slightly campanulate spicular sheath (arrow), lateral view. B. SEM micrograph of the anterior extremity of Monodontus sp. from Sigmodon toltecus showing the mouth opening, paired cutting plates and cervical papillae (arrow), ventral view. C. Cross section at midbody showing features of the synlophe of female Vexillata vexillata from Heteromys gaumeri. D. Male caudal bursa of Vexillata vexillata from Heteromys gaumeri, ventral view. E. Cross section at midbody showing features of the synlophe of male Heligmosomoidea gen. sp. cf. Vexillata from Ototylomys phyllotis. F. Cross section at midbody showing features of the synlophe of female Carolinensis sp. from Peromyscus yucatanicus. G. Cross section at midbody showing features of the synlophe of male Hassalstrongylus aduncus from Sigmodon toltecus. H. Cross section at midbody showing features of the synlophe of female Hassalstrongylus musculi from Oligoryzomys fulvescens. I. Male caudal bursa of Hassalstrongylus musculi from Ototylomys phyllotis, dorsal view. J. SEM micrograph of female Heligmostrongylus sp. from Peromyscus yucatanicus showing the discontinuous ridges, lateral view. K. Male caudal bursa of Heligmostrongylus sp. from Peromyscus yucatanicus, ventral view. L. Cross section at midbody of female Heligmonellidae gen. sp. from Sigmodon toltecus showing the absence of synlophe. Abbreviations: r, right side; v, ventral side. All cross sections of the synlophe orientated as in figure C.