New Data on Pterygodermatites (Pterygodermatites) plagiostoma Wedl, 1861 (Nematoda, Rictulariidae) Parasite of the Algerian Hedgehog Atelerix algirus Linnaeus, 1758 (Eulipotyphla: Erinaceidae) from the Canary Islands †

SIMPLE SUMMARY: A redescription of Pterygodermatites (Pterygodermatites) plagiostoma (Nematoda, Rictulariidae) is made by means of light and scanning electron microscopy, including the first data on male specimens. The morphologic study was based on specimens recovered from two Algerian hedgehogs from Tenerife and Gran Canaria islands (Canary Archipelago, Spain). The main differential characteristics of P. (P.) plagiostoma males are the number of cuticular projection pairs, the number of precloacal fans, and the size of spicules. The cloacal papillae are arranged according to the Ascaridida type, with two precloacal pairs, an unpaired precloacal papilla, one pair lateral to the cloaca, six postcloacal pairs, and a pair of phasmids. Females are mainly characterized and differentiated by the number of prevulvar pairs of cuticular projections, by the total number of cuticular projection pairs, by the level of differentiation from combs to spines and by the position of the vulva in relation to the esophagus–intestine junction. The comparison with species of the subgenus P. (Pterygodermatites) shows P. (P.) plagiostoma as a species clearly differentiated from the remaining species of this subgenus. ABSTRACT: A redescription of the rictulariid nematode Pterygodermatites (Pterygodermatites) plagiostoma Wedl, 1861, is made by means of light and scanning electron microscopy, including the first data on male specimens. The morphologic study was based on specimens recovered from two Algerian hedgehogs (Atelerix algirus) from Tenerife and Gran Canaria islands (Canary Archipelago, Spain). The main characteristics of P. (P.) plagiostoma males are the presence of 49–53 pairs of cuticular projections, the presence of one or two midventral precloacal fans (generally one), and the size of two unequal spicules, measuring 98–123 µm (right spicule) and 185–236 µm (left spicule). The cloacal papillae are arranged according to the Ascaridida type. They include two precloacal pairs, an unpaired precloacal papilla, one pair lateral to the cloaca, six postcloacal pairs, and a pair of phasmids near the tail tip. Females are mainly characterized by the presence of 71–77 pairs of cuticular projections, with 43–46 pairs of prevulvar combs, by the differentiation from combs to spines at the level of or slightly posterior to the vulva and by the position of the vulva, located posteriorly to the esophagus–intestine junction. Clear differences were found between P. (P.) plagiostoma and related species of the subgenus P. (Pterygodermatites).