Parapharyngodonn. spp. (Nematoda: Pharyngodonidae) Parasites of Hylid Frogs from Mexico and Review of Species Included in the Genus

Abstract

Two new species of Parapharyngodon Chatterji, 1933, parasitizing 3 species of hylid frogs (Diaglena spatulata, Triprion petasatus, and Trachycephalus typhonius) from Mexico are described. The 2 new species share the presence of a gubernaculum with Parapharyngodon lamothei and belong to the group of those species with short spicule; both differ from the remaining species of the genus in the papillar pattern on ventrolateral and dorsal lips and in the thickness of cuticular annulations and cuticular ornamentation in the female specimens. These are the third and fourth reports of Parapharyngodon spp. parasitizing hylid frogs. In addition to the egg characteristics, we propose that length of the lateral alae is also a taxonomically relevant feature to differentiate species of the genus. A bibliographic review of all species historically assigned to Parapharyngodon is given, including those that have been declared species inquirenda, or transferred to other genera and those that are considered valid.

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)

“…The high species richness of Parapharyngodon is probably related to the geographical and environmental heterogeneity of this region, and was recently revealed by parasitological surveys of host species not considered in previous studies (Jiménez et al 2008, Bursey and Goldberg 2015, Velarde-Aguilar et al 2015, Garduño-Montes de Oca et al 2016). …”

Two new species of Parapharyngodon parasites of Sceloporus pyrocephalus, with a key to the species found in Mexico (Nematoda, Pharyngodonidae)

“… Parapharyngodon ayotzinapaensis sp. n. is the 79 th species assigned to Parapharyngodon and the 48 th valid species of the genus ( Velarde-Aguilar et al 2015 ; Bursey and Goldberg 2015 ). It is distinguished from the other Parapharyngodon species by a combination of characters including the possession of 4 pairs of caudal papillae, an echinate anterior cloacal lip, lateral alae covering the last third of body, spicule length representing 3.614% of body length, prebulbar ovaries coiling around prebulbar esophagus and eggs with punctuated shell and without alae.…”

“…Finally, spicule length/body length ratio is greater in Parapharyngodon grenadaensis (4.488%) and Parapharyngodon colonensis (3.765%) than in Parapharyngodon ayotzinapaensis (3.614%). Therefore, we consider Parapharyngodon ayotzinapaensis to represent a new species, the 10th recorded in Mexico ( Bursey and Goldberg 2005 , Bursey et al 2013 , Velarde-Aguilar et al 2015 , Bursey and Goldberg 2015 ).…”

“…Thirteen of these species have echinate precloacal lip and lateral alae as the second new species described herein; of these, only Parapharyngodon grenadaensis , Parapharyngodon colonensis and Parapharyngodon ayotzinapaensis share the presence of prebulbar ovaries and a punctuate egg shell with Parapharyngodon tikuinii . Nonetheless, Parapharyngodon tikuinii differs from Parapharyngodon grenadaensis , Parapharyngodon colonensis and Parapharyngodon ayotzinapaensis in the lateral alae extension (which start at level of nerve ring and end at level of precloacal papillae in these three species, whereas in Parapharyngodon tikuinii lateral alae cover exclusively the last portion of the body); in addition, spicule length-total body length ratio is greater in Parapharyngodon grenadaensis (4.488%), Parapharyngodon colonensis (3.765%) and Parapharyngodon ayotzinapaensis (3.614%) than in Parapharyngodon tikuinii (3.287%) ( Bursey and Goldberg 2005 , Bursey et al 2013 , Velarde-Aguilar et al 2015 , Bursey and Goldberg 2015 ). Finally, males of Parapharyngodon grenadaensis and Parapharyngodon colonensis have three bilobed lips which are simple in Parapharyngodon tikuinii .…”

“…Recently, the validity of species of Parapharyngodon Chatterji, 1933 was reviewed ( Velarde-Aguilar et al 2015 , Bursey and Goldberg 2015 ). In accordance with these authors, of the 78 Parapharyngodon species assigned to this genus, only 47 have been properly described, and recognized as valid species.…”