A revision of the taxonomy of pentastomid parasites (genusRaillietiella Sambon, 1910) from American snakes and amphisbaenians

Abstract

Two species of pentastomid belonging to the genusRaillietiella Sambon, 1910 have been described from American snakes although their characters overlap and they are only differentiated on criteria now known to be unreliable (Self, 1969). We show that the species can be readily distinguished on the sole criterion of the form of the male copulatory spicule. There is confusion in many of the early records about hosts. After untangling these records, as far as possible, we postulate that the two species have allopatric distributions, one being Neotropical and the other Nearctic. A new species,R. crotali, is described, which is close to the Neotropical speciesR. furcocera, but it has much smaller hooks. Closely related species from the Old World utilize vertebrates as intermediate hosts and this is almost certainly true of the species described here. Given this, the very considerable differences in dietary regimen of the various hosts harbouring ‘R. furcocerca’, strongly suggest that there may be more than one species involved. R. gigliolii from the South American amphisbaenianAmphisbaena alba is also described since, historically, it has been confused withR. furcocerca. The systematics of these snake and amphisbaenian raillietiellids is discussed. ac]19821203