Parasites of an Arctic scavenger; the wolverine (Gulo gulo).

Sophie E Watson,Frank Hailer,Nicolas Lecomte,Rajnish Sharma,Sarah E Perkins,Malik Awan,Vincent L’Hérault,Pratap Kafle,Emily J Jenkins

doi:10.1016/j.ijppaw.2020.10.004

Abstract

Parasites are fundamental components within all ecosystems, shaping interaction webs, host population dynamics and behaviour. Despite this, baseline data is lacking to understand the parasite ecology of many Arctic species, including the wolverine (Gulogulo), a top Arctic predator and scavenger. Here, we combined traditional count methods (i.e. adult helminth recovery, where taxonomy was confirmed by molecular identification) with 18S rRNA high-throughput sequencing to document the wolverine parasite community. Further, we investigated whether the abundance of parasites detected using traditional methods were associated with host metadata, latitude, and longitude (ranging from the northern limit of the boreal forest to the low Arctic and Arctic tundra in Nunavut, Canada). Adult parasites in intestinal contents were identified as Baylisascaris devosi in 72% (n = 39) of wolverines and Taenia spp. in 22% (n = 12), of which specimens from 2 wolverines were identified as T. twitchelli based on COX1 sequence. 18S rRNA high-throughput sequencing on DNA extracted from faeces detected additional parasites, including a pseudophyllid cestode (Diplogonoporus spp. or Diphyllobothrium spp.), two metastrongyloid lungworms (Angiostrongylus spp. or Aelurostrongylus spp., and Crenosoma spp.), an ascarid nematode (Ascaris spp. or Toxocara spp.), a Trichinella spp. nematode, and the protozoan Sarcocystis spp., though each at a prevalence less than 13% (n = 7). The abundance of B. devosi significantly decreased with latitude (slope = -0.68; R2 = 0.17; P = 0.004), suggesting a northerly limit in distribution. We describe B. devosi and T. twitchelli in Canadian wolverines for the first time since 1978, and extend the recorded geographic distribution of these parasites ca 2000 km to the East and into the tundra ecosystem. Our findings illustrate the value of molecular methods in support of traditional methods, encouraging additional work to improve the advancement of molecular screening for parasites.

Highlights

Representing over 50% of all organisms on Earth, parasites are a fundamental component within all ecosystems –shaping interaction webs as well as host population dynamics and behaviour (Dobson et al, 2008; Hudson et al, 2006; Marcogliese, 2001)
International Journal for Parasitology: Parasites and Wildlife 13 (2020) 178–185. We use both a traditional parasite count method and 18S rRNA high-throughput sequencing to characterise the parasite commu nity of wolverines from Nunavut, Canada
We combined adult helminth recovery and 18S rRNA high-throughput sequencing of DNA extracted from faecal and small intestinal samples to provide compre hensive insight into the gastrointestinal parasite community of wolver ines

Summary

Introduction

Representing over 50% of all organisms on Earth, parasites are a fundamental component within all ecosystems –shaping interaction webs as well as host population dynamics and behaviour (Dobson et al, 2008; Hudson et al, 2006; Marcogliese, 2001). Even at high latitudes where biological diversity is purported to be generally low (such as the Arctic), parasite communities can be diverse and often more species-rich than those of their vertebrate hosts (Hoberg et al, 2008; Kutz et al, 2009). Over 60 species of parasite are described in four ungulate species of High Arctic Greenland and North America (Kutz et al, 2012). Such descriptions highlight the extensive distribution of parasites throughout Arctic hosts. One expected consequence of warming air temperatures and increased precipitation in the northern hemisphere is a significant increase in the northern expansion of parasites and their hosts into regions that were previously inhospitable to them

Methods

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Conclusion