Heligmosomoidea Travassos
Creators: name: Panti-May, Jesús Alonso
name: Moguel-Chin, Wilson Isaias
name: Hernández-Mena, David Iván
name: Cárdenas-Vargas, Miguel Humberto
name: Torres-Castro, Marco
name: García-Prieto, Luis
name: Digiani, Maria Celina
name: Hernández-Betancourt, Silvia F.
name: Vidal-Martínez, Víctor Manuel
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Nematoda
Chromadorea
Rhabditida

description: Heligmosomoidea gen. sp. cf. Vexillata
Site of infection: Small intestine
Host species: Ototylomys phyllotis
Localities: Kuncheil cattle ranch, Papam ranch (Yucatan), Jolie Jungle eco-hotel, Balam Nah eco-hotel, and David Gustavo community (Quintana Roo)
Specimens deposited: CNHE 12005‒12009
GenBank accession numbers: OR271665, OR271682
Comments: The specimens found in this study had a cephalic vesicle and a buccal capsule reduced to an annulus. Females were monodelphic and lack a caudal spine. The synlophe showed 15 ridges with struts, including a careen moderately developed composed of two stout ridges, an axis of orientation of the ridges oblique to subfrontal, and a slight decreasing gradient of the ridge size from right to left on the dorsal side (Figure 4E). Males possessed a subsymmetrical caudal bursa with a pattern of type 2-2-1, spicules filiform and a gubernaculum. In females, at the ovejector level, the synlophe was highly modified, with hypertrophy and loss of orientation of the ridges on the whole-body circumference.
The combination of the abovementioned characters allows us to place these specimens undoubtedly in the Heligmosomoidea excluding, among these, the families Herpetostrongylidae, Nicollinidae, Heligmosomidae and Viannaiidae (Beveridge et al. 2013). Particularly, the bursal pattern 2-2-1, the synlophe with careen, the ridges continuous and the presence of gubernaculum approach them to the Nippostrongylinae (Heligmonellidae) or, to a lesser degree, to species of Vexillata (Ornithostrongylidae), all parasites of rodents. The cosmopolitan Nippostrongylinae are typically parasites of cricetids, whereas species of the New World genus Vexillata have been reported from geomyids and heteromyids and from leporids of the genus Sylvilagus (Digiani et al. 2007). The only carenated Nippostrongylinae from the New World is, up to now, the monotypic genus Mazzanema Digiani, Notarnicola & Paulos, 2013, with a species parasitic in Holochilus chacarius from Argentina, characterized by a female synlophe of 19 ridges and a male bursal pattern 1-3-1 (Digiani et al. 2013). Attending to the main synlophial and bursal characters of the present specimens, plus the fact that the host is a cricetid, they could be assigned to a genus and species not yet described in the Nippostrongylinae. However, the phylogenetic analysis based on the 28S sequences recovered them as sister species of V. vexillata, and not of the other Nippostrongylinae comprised in the study. Morphological characters that approach these specimens to Vexillata are the careen made up of two ridges, the axis of orientation subfrontal, the bursal pattern 2-2-1, the bursal rays 8 filiform, and the distal division of the dorsal ray. However, the 14 known species of Vexillata are characterized by fewer ridges (9-12), ridges of the careen long and thin; usually lack modifications of the synlophe at the ovejector level and, up to now, have never been reported from cricetids. The taxonomic value of all these characters (morphology, genetics, host specificity) will be assessed with an integrative approach. By the moment the scenario is rather puzzling, and we prefer to consider these specimens from O. phyllotis as Heligmosomoidea gen. sp. cf. Vexillata.
This is the first record of the Heligmosomoidea for O. phyllotis.
description: Published as part of 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, pp. 205-240 in Zootaxa 5357 (2) on pages 217-219, DOI: 10.11646/zootaxa.5357.2.3, http://zenodo.org/record/10017978