Besides the common toad from which this roundworm was first described, it has been found in the common spadefoot toad (Pelobates fuscus), the common frog (Rana temporaria), the moor frog (Rana arvalis), the agile frog (Rana dalmatina), the European fire-bellied toad (Bombina bombina), the yellow-bellied toad (Bombina variegata), water frogs (Pelophylax spp.) and the European green toad (Bufo viridis).
Pelophylax, a genus of frog widespread in Eurasia, with a few species ranging into northern Africa
Hylarana seems to form a clade together with the similarly revalidated genera Pulchrana and Sylvirana, and presumably also Hydrophylax as well as some species presently placed in Pelophylax (e.g. Kokarit Frog, "P." lateralis).