Oligacanthorhynchus microcephalus (Rudolphi)

Site of infection: Intestines.

Host species: Didelphis virginiana .

Localities: Umán, Mérida (Yucatán), Campeche, and Chencoh (Campeche).

Prevalence: 83.3% (5/6).

Mean intensity: 11.6 (range 1‒29).

Specimens deposited: CNHE 12892‒12895.

GenBank accession numbers: PP662468, PP662469.

Comments: The present material conformed to the descriptions by Richardson et al. (2014) and López-Caballero et al. (2015). Worms elongated and narrowly constricted at anterior end. Proboscis ovoid, 300–320 long by 300 wide, armed with six longitudinally arranged spiral rows of six shallowly rooted hooks each. The length of hooks decreases posteriorly: first hooks 75‒80, second hooks 50‒65, third hooks 45‒58, fourth hooks 40‒45, fifth hooks 30‒32, sixth hooks 20‒25 (Figure 6C). Male trunk 99,200–140,600 long by 4,000 –7,000 wide. Female trunk 106,500–222,000 long by 4,000 –10,000 wide. Eggs ellipsoid, 75–85 long by 30–42 wide.

Oligacanthorhynchus microcephalus has been previously reported from opossums ( D. marsupialis, D. virginiana and P. vossi) in Campeche, Chiapas, Colima, Guanajuato, Hidalgo, Michoacán, Morelos, Oaxaca, Tabasco, Veracruz, and Yucatán (see García-Prieto et al. 2012; Acosta-Virgen et al. 2015; López-Caballero et al. 2015). This study adds new locality records in Yucatán and Campeche.