Strongyloides sp.

Site of infection: Small intestine.

Host species: Philander vossi.

Locality: Chetumal (Quintana Roo).

Prevalence: 100% (1/1).

Intensity: 5.

Specimen deposited: CNHE 12883.

Comments: The specimens consist of five females with general morphology of the genus Strongyloides (dos Santos et al. 2010). The anterior end was truncated and presented stoma; however, details of this structure could not be observed due to poor preservation. Absence of cephalic vesicle and caudal spines. Slender nematodes, gradually tapering anteriorly from the region of the esophagus (Figure 4E); tapering more so posteriorly from region of anus (Figure 4F). Bucal capsule and synlophe absent. Body length 2,600 ‒3,480 and body width 30‒40. Didelphic females (Figure 4G). Vulva no prominent, 1,170 ‒1,230 from the posterior end. Anus opens 40‒50 from tip of tail (Figure 4F). Eggs ovoid, 48‒62 long by 25‒38 wide. The morphological similarity among species of Strongyloides has frustrated taxonomic work on the genus (Viney et al. 1991). While features of the parasitic female such as the shape of the stoma, the type of ovary, the shape of the tail, and the number of lobes on the circumoral elevation have been useful to differentiate many species of the Strongyloides, other species cannot be separated (Speare 1989). On the other hand, features of free-living males such as the shape of spicules and gubernaculum, arrangement of caudal papillae are important criteria for separating some species (Viney et al. 1991). Considering the present morphological data, the specimens were designed as Strongyloides sp. until more morphological and molecular evidence is generated.

This is the first record of Strongyloides from P. vossi in Mexico.