Review: Invasive species and their parasites: eastern cottontail rabbit Sylvilagus floridanus and Trichostrongylus affinis (Graybill, 1924) from Northwestern Italy
Researchers Tizzani, Catalano, Rossi, Duignan, and Meneguz published an article entitled, “Invasive species and their parasites: eastern cottontail rabbit Sylvilagus floridanus and Trichostrongylus affinis (Graybill, 1924) from Northwestern Italy” in the Parasitology Research journal in 2014. The article discusses the possibility of other parasite species being present in the invasive eastern cottontail Sylvilagus floridanus in Europe other than the species that have already been reported. This article presents the first documentation of the nematode Trichostrongylus affinis in a S. floridanus in Europe but provides no concrete evidence that explains the nematode’s presence in the invasive cottontails of Europe.
The researchers seek to find out whether or not there are other parasite species in the In 2010, 51 male and 50 female cottontails were gathered from an agricultural plain in Italy. Their gastrointestinal tracts were isolated and dissected so that their intestinal contents could be examined with a stereoscope to collect parasitic worms. The researchers found the nematode T. affinis After statistical analysis the sex of the cottontails was concluded to have no effect on the presence of T. affinis but young cottontails were more likely to have the nematode than the adult cottontails were. The researchers give possible reasons for the decrease in parasite diversity from the cottontail’s natural range to its inhabitance in Europe, including that some parasites lacked resources to thrive. The overlapped inhabitance of the cottontail and the native European brown hare (Lepus europaeus) may facilitate the transmission of T. affinis. The discovery of T. affinis in the cottontails in Europe may contribute to the study of the competition between the cottontail and hare but more research of parasites in both animals needs to be conducted.
The extent of the researchers’ analysis consists of the identification of the T. affinis and the calculation of its prevalence amongst different ages and sexes of the cottontails. The researchers only provide potential explanations of why only a few nematode species out of the eighteen known to affect the eastern cottontail are being seen in Italy. Evidence from data is not used to support their suggestions that the eastern cottontails introduced to Europe came from a small portion of the whole cottontail population or that conditions for the parasites’ transmission or population development were not met. The researchers found T. affinis in the cottontails of Europe but fail to provide definite reasons as to why it was found in their sample of cottontails.
Although the article does provide the first report of T. affinis in the invasive cottontails of Europe, it does not provide much analysis of the nematode. However, this article suggests possible causes of the T. affinis population distribution which may lead to future studies about that and the effects the parasite species may have on the competition between the invasive S. floridanus and native L. europaeus.
References
Tizzani, P., Catalano, S., Rossi, L., Duignan, P. J., & Meneguz, P. G. (2014). Invasive species and their parasites: eastern cottontail rabbit Sylvilagus floridanus and Trichostrongylus affinis (Graybill, 1924) from Northwestern Italy. Parasitology Research, 113(4), 1301-1303. doi:10.1007/s00436-014-3768-1
