Case Report: Invasive Pentastomes, Raillietiella orientalis (Sambon, 1922), in a Free-Ranging Banded Water Snake (Nerodia fasciata) in North Central Florida, USA

Abstract

Raillietiella orientalis is an obligate, crustacean parasite that resides in the respiratory tract of definitive snake hosts. Common throughout southeastern Asia and Australia, R. orientalis is believed to have been introduced into southern Florida, United States along with Burmese pythons ( Python bivittatus ) in the 1990s. While the invasive range of Burmese pythons is restricted to southern Florida, R. orientalis has advanced north in the state in native snake species. R. orientalis were recovered from the lungs, trachea, oral cavity, and esophagus of an emaciated adult female free-ranging banded water snake ( Nerodia fasciata ) in north central (Alachua County), Florida, USA. Concurrent findings included the recovery of Ochetosoma sp. trematodes from the oral cavity, and multifocal dermal lesions consistent with snake fungal disease ( Ophidiomyces ophiodiicola ). This is the first report of R. orientalis in north central Florida, well outside the invasive range of the Burmese python, documenting the substantial northward expansion of the known geographical range of this invasive pentastome in Florida.

The invasive pentastome Raillietiella orientalis in a banded water snake from the pet trade

“…Nucleic acids were extracted from a sample of the parasite, and a portion of the small subunit ribosomal RNA gene was amplified and commercially sequenced bidirectionally, as done in prior research. 16 The determined sequence was 100% identical to the R. orientalis sequences in GenBank. We also microscopically examined wet mounts of a 0.0104-g fraction of a small fecal sample on a series of slides and counted 1,756 embryonated pentastome eggs (Fig.…”

“…13 Although R. orientalis was initially restricted to south Florida, 11 it has now spread north rapidly, occupying much of peninsular Florida. 12,16 A concerned owner posted on a social media site in January 2022 that their pet banded water snake had expectorated a parasite while producing an audible retching sound. The snake's owner had previous experience in raising Nerodia and noticed that this snake had failed to grow and gain weight in the 5 mo that they had the snake, despite regular, routine feeding and no display of abnormal activity.…”

Burmese pythons in Florida: A synthesis of biology, impacts, and management tools

“…Indeed, all infected native North American snake species are immunologically naïve to this novel parasite because they did not co-evolve with R. orientalis, thus, they are likely susceptible to exacerbated impacts of infection . Furthermore, the impacts of spillover exceed the geographic range of pythons, as native R. orientalis-infected snakes have been documented more than 350 km north of the northernmost infected python (Farrell et al 2019;Miller et al 2020;Walden et al 2020). R. orientalis infect widespread and abundant native and non-native intermediate invertebrate, frog, and lizard hosts (Palmisano et al 2022), and widespread generalist intermediate hosts have facilitated the spread of non-native pentastomes through native snake communities in tropical Australia (Kelehear et al 2013(Kelehear et al , 2014.…”

First record of an Asian tongueworm, Raillietiella orientalis (Pentastomida: Raillietiellidae), parasitizing a Tokay Gecko, (Gekko gecko, Squamata: Gekkonidae): a novel interaction between two non-native species in Florida

“…1 insert), an obligate parasite that infects the lungs of snakes as its primary host, is native to Asia, Africa, and possibly Italy (Ali et al 1982;Christoffersen and De Assis 2013); it is co-invasive with the Burmese Python (Python bivittatus) in Florida (Miller et al 2018). Raillietiella orientalis has spilled over from pythons to infect 14 of Florida's native species of snakes (Miller et al 2018(Miller et al , 2020Metcalf et al 2019), and is expanding its range northward beyond the range of the Burmese Python via these highly competent novel snake hosts (Miller et al 2020), with R. orientalis detected in native snakes as far north as Alachua County (Walden et al 2020). Herein we report the first record of R. orientalis parasitizing G. gecko.…”

“…The exploitation of novel hosts by R. orientalis might result from its ability to exhibit hostspecific phenotypic plasticity (Westfall et al 2019), which, when coupled with the plethora of immunologically naïve hosts within the pentastomes' North American invasive range, may ultimately enable this parasite to infect a variety of novel intermediate and definitive hosts in Florida. Gekko gecko has established itself as far north as Leon County, Florida (Means 1996), which borders Georgia and is substantially farther north than the current northernmost record of R. orientalis from Alachua County (Walden et al 2020). Thus, the potential exists for R. orientalis to expand its range farther northward through parasitism of G. gecko.…”