New records of helminths of Sceloporus pyrocephalus Cope (Squamata, Phrynosomatidae) from Guerrero and Michoacán, Mexico, with the description of a new species of Thubunaea Seurat, 1914 (Nematoda, Physalopteridae)

Abstract

A total of 61 specimens of the Red-headed Spiny Lizard Sceloporus pyrocephalus Cope (Phrynosomatidae) collected during the breeding season (June/July 2003, 2004 and 2005) from Western Mexico were examined for helminths. The morphological characterization of the helminths found was made through light microscopy and scanning electron microscopy. Nine taxa of helminths were identified, two cestodes: Mesocestoides sp. and Oochoristica sp., and seven nematodes: Parapharyngodon ayotzinapaensis Garduño-Montes de Oca, Mata-López & León-Règagnon, 2016, Parapharyngodon tikuinii Garduño-Montes de Oca, Mata-López & León-Règagnon, 2016, Parapharyngodon sp., Physalopterinae gen. sp., Skrjabinoptera scelopori Caballero-Rodríguez, 1971, Strongyluris similis Caballero, 1938 and a new species of Thubunaea Seurat, 1914. Larvae of Mesocestoides sp. and Physalopterinae gen. sp. were found in the body cavity and digestive tract, respectively. Excluding the species of Parapharyngodon Chatterji, 1933, S. pyrocephalus is recorded for the first time as a host of the remaining seven taxa of helminths. Additionally, Thubunaea leonregagnonae sp. n. is described and illustrated as a new nematode species, parasite of S. pyrocephalus from Mexico. This new species can be differentiated from the majority of its congeners by the absence of spicules, the particular pattern of caudal papillae in males and the small ratio of oesophagus length:male total body length (0.1–0.16).

Redescription of Thubunaea schukurovi Annaev, 1973 from Ablepharus chernovi, with notes on the members of Thubunaea (Spirurida: Physalopteridae) from the Palaearctic and Indomalayan realms

“…The asymmetrical pseudolabia, armed with more pronounced and of different size teeth on one of the pseudolabia is a characteristic of the genus Physalopteroides , members of which are often described with well-defined pseudolabia and a cephalic collarette at their base (see Bursey & Goldberg, 2001; Bursey & Goldberg, 2016). All other species within the genus Thubunaea are characterized by two rounded, inconspicuous pseudolabia each bearing three similar in size teeth and there is no groove of cephalic collarette at their base (Seurat, 1914; Baylis, 1926; Ortlepp, 1931; Telford Jr, 1965; Sharpilo, 1966; Babero & Matthias, 1967; Annaev, 1973; Bursey & Goldberg, 1991; Moravec et al , 1997; Pazoki & Rahimian, 2014; Garduño-Montes de Oca et al , 2017; Ramallo et al , 2017). Based on the above discussion, we consider the species described by Deshmukh (1969a) as belonging to the genus Physalopteroides and propose the new combinations Physalopteroides singhi , Physalopteroides brooki , Physalopteroides aurangabadensis and Physalopteroides syedi .…”

“…Some subsequent studies listed both species among the Thubunaea spp. without spicules (Bursey & Goldberg, 1991;Pazoki & Rahimian, 2014;Garduño-Montes de Oca et al, 2017;Ramallo et al, 2017) although, to the best of our knowledge, there are no morphological studies on these species documenting the lack of spicules.…”