Microphallidae, Ward, 1901

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 : 211-212

Microphallidae gen. sp.

Site of infection: Small intestine

Host species: Peromyscus yucatanicus

Locality: Molas farm and Aak ecological park (Yucatan)

Specimens deposited: CNHE 11958

Comments: The trematodes found in P. yucatanicus presented characteristics of Microphallidae ( Deblock 2008) , i.e., tiny adults, 500±300; body flattened dorsoventrally; tegument spinous; two medium-sized suckers, well separated; oral sucker subterminal and ventral sucker post-equatorial; pharynx present; caeca widely divergent, not extending beyond ventral sucker; two testes, lateral, symmetrical, and post-ovarian; male terminal genitalia intercaecal, anterior to ventral sucker; ovary post-caecal, pretesticular, aporal at the level of ventral sucker and submedian; vitellarium follicular, in two symmetrical clusters post-caecal; eggs numerous unembryonated in utero. The specimens found in Yucatan had a body pyriform; suckers almost the same size; prepharynx absent; genital pore dextral to ventral sucker; and uterus extending to oral sucker. The main measurements of our specimens were: body length 171.25 and maximum width 97.5; oral sucker 37.5 long by 40 wide; pharynx 16.25 long by 15 wide; ventral sucker 23.75 long by 25 wide; and eggs 21.25 long by 12.5 wide. The male and female genitalia and esophagus could not be clearly observed due to the large number of eggs present in the uterus ( Figure 2D ), which did not allow us to identify the specimens at the genus level.

This is the first record of Microphallidae in mammals from Mexico and for P. yucatanicus .

Figures

FIGURE 2. A.Adult specimen of Scaphiostomum sp. from Heteromys gaumeri, ventral view. B. Adult specimen of Skrjabinus sp. from Heteromys gaumeri, ventral view. C. SEM micrograph of Skrjabinus sp. from Heteromys gaumeri showing the ventral surface and the acetabulum, ventral view. D. Adult specimen of Microphallidae gen. sp. from Peromyscus yucatanicus, ventral view.