Redescriptions of the Nematodes Litomosoides patersoni (Mazza, 1928) (Onchocercidae) and Stilestrongylus stilesi Freitas, Lent, And Almeida, 1937 (Heligmonellidae) Parasites of Holochilus chacarius (Rodentia, Cricetidae) From Salta, Argentina

Abstract

Two nematode species are redescribed from the type host species Holochilus chacarius Thomas (Rodentia, Cricetidae, Sigmodontinae) and from the type locality of 1 of them, i.e., Ingenio San Martín de Tabacal, Salta Province, Argentina. Rodents were deposited at the Colección Mamíferos Lillo, Tucumán, Argentina. Litomosoides patersoni (Mazza, 1928) (Onchocercidae) possesses a buccal capsule with irregular external walls, a buccal cavity smooth, becoming thinner near the oral opening, a complete set of head papillae, 3-6 pairs of cloacal papillae, and the " sigmodontis " type of spicules. Filarioids were found in 3 of 17 examined hosts. Stilestrongylus stilesi Freitas, Lent, and Almeida, 1937 (Heligmonellidae), whose description was based on male specimens, was found in all 17 of the examined hosts. Here, we describe the female and the synlophe of both sexes. Females are characterized by a short uterus with less than 25 eggs, short ovejector, short and conical tail, and the posterior extremity strongly invaginated in a cuticular expansion usually harboring 1 to several eggs. The synlophe is characterized by 29-31 sub-equal cuticular ridges at the mid-body, with single (in males) or double (in females) axis of orientation of the ridges. The present work validates and enlarges the original descriptions of both species and assigns the specimens from L. patersoni, recovered from the type locality and the type host species, as neotypes.

Mazzaneman. gen. andMazzanema fortuitan. comb. forLongistriata fortuitaFreitas, Lent, and Almeida, 1937 (Nematoda: Heligmonellidae), a Parasite of the Marsh RatHolochilus chacarius(Rodentia: Cricetidae) from Northern Argentina

“…However, the description by Freitas et al (1937) is accurate enough: the presence of longitudinal ridges salient and transversely striated is remarked, and particularly the description and illustration of the caudal bursa, spicules, and gubernaculum are very clear and allow us to easily distinguish the specimens described as L. fortuita. Other species described by Freitas et al (1937) as coparasitic with L. fortuita, i.e., S. stilesi and H. argentinus, were also identified in the hosts examined during this work, but both are easily differentiated from L. fortuita by characters of the synlophe, caudal bursa, and spicules in males and by the synlophe and shape of the posterior extremity in females (see redescriptions of H. argentinus in Durette-Desset [1968] and of S. stilesi in Notarnicola et al [2010]). Concerning the females of L. fortuita, they were not described or identified by Freitas et al (1937) and the matching of males and females of the species was possible through the study of the synlophe.…”

“…The fate of these species was diverse: L. argentina was redescribed and, on the basis of the synlophe, transferred to Hassalstrongylus Durette- Desset, 1971 (Heligmonellidae); H. mazzai was also transferred to Hassalstrongylus, although its synlophe remains unknown (Durette-Desset, 1971). Finally, S. stilesi was redescribed on new material collected and its position in the genus Stilestronglus (as redefined by Durette-Desset, 1971) confirmed (Notarnicola et al, 2010).…”

Description of Litomosoides ysoguazu n. sp. (Nematoda, Onchocercidae), a parasite of the tuft-toed rice rat Sooretamys angouya (Fischer) (Rodentia: Cricetidae), and a first record of L. esslingeri Bain, Petit & Berteaux, 1989 in Paraguay

“…Notarnicola, 2005 (44.8-72.3 mm); L. taylori Guerrero & Bain, 2011 (mean 54.3 mm); and L. circularis (von Linstow, 1899) (65 mm). Moreover, the new species can be differentiated from L. patersoni in having a buccal capsule with a thickening instead of irregular walls, and by the slender microfilaria instead of a stout one (Notarnicola et al, 2010); from L. oxymycteri by the absence of a precloacal papilla (Notarnicola et al, 2000); from L. anguyai and L. nasuti in having no salient amphids and a complete set of head papillae (Notarnicola et al, 2002;Notarnicola & Navone, 2009); from L. navonae in having a more posteriorly located vulva (mean 2,023 vs 1,359 lm from the anterior extremity) and microfilaria with a sheath visible only at the anterior extremity (Notarnicola, 2005); from L. taylori by the presence of a thickening in the buccal capsule instead of irregular walls ; and from L. circularis by a shorter right spicule (mean length 80-110 vs 98-121 lm) and different spicular ratio (mean 3.5 vs 2.8) .…”

Litomosoides pardinasi n. sp. (Nematoda, Onchocercidae) from two species of cricetid rodents in northern Patagonia, Argentina

“…In the last 10 years, five new species of Litomosoides were described in cricetid rodents in central and northeastern Argentina, and L. patersoni (Mazza 1928) was found in the type host and type locality in the northwest of the country and has been redescribed (Notarnicola 2005;Notarnicola et al 2000Notarnicola et al , 2010b.…”