Qualitative community stability determines parasite establishment and richness in estuarine marshes

Tavis K Anderson,Michael V.K Sukhdeo

doi:10.7717/peerj.92

Tavis K Anderson, Michael V.K Sukhdeo

Open Access

https://doi.org/10.7717/peerj.92

Copy DOI

Abstract

The establishment of parasites with complex life cycles is generally thought to be regulated by free-living species richness and the stability of local ecological interactions. In this study, we test the prediction that stable host communities are prerequisite for the establishment of complex multi-host parasite life cycles. The colonization of naïve killifish, Fundulus heteroclitus, by parasites was investigated in 4 salt marsh sites that differed in time since major ecological restoration, and which provided a gradient in free-living species richness. The richness of the parasite community, and the rate at which parasite species accumulated in the killifish, were similar between the low diversity unrestored site and the two high diversity (10- and 20-year) restored marsh sites. The parasite community in the newly restored marsh (0 year) included only directly-transmitted parasite species. To explain the paradox of a low diversity, highly invaded salt marsh (unrestored) having the same parasite community as highly diverse restored marsh sites (10 and 20 yrs) we assessed qualitative community stability. We find a significant correlation between system stability and parasite species richness. These data suggest a role for local stability in parasite community assembly, and support the idea that stable trophic relationships are required for the persistence of complex parasite life cycles.

Highlights

Parasites are considered to be ubiquitous components of ecosystems and the trophic strategy may represent more than 50% of potential interactions in food webs (Price, 1980; de Meeus & Renaud, 2002)
A logical extension of this premise is that parasite species that rely on trophic interactions for transmission will only be present when stable predator-prey trophic links exist in ecosystems (Marcogliese, 2002; Anderson & Sukhdeo, 2010; Anderson & Sukhdeo, 2011; Anderson & Sukhdeo, 2013)
The range of stability documented across our food webs suggests that there may be a critical threshold in the stability of host communities that is required for the persistence of complex life cycle parasites

Summary

Introduction

Parasites are considered to be ubiquitous components of ecosystems and the trophic strategy may represent more than 50% of potential interactions in food webs (Price, 1980; de Meeus & Renaud, 2002). This pervasive nature is reflected in their many roles in the regulation of competitive and predator/prey interactions (Hatcher, Dick & Dunn, 2006), community structure (Dobson & Hudson, 1986; Wood et al, 2007), and ecosystem energy flow (Mouritsen & Jensen, 1994; Kuris et al, 2008). The underlying principle being that parasite life strategies are integrally coupled with populations of hosts, and that these hosts are critical for the parasites, and to the dynamics of the free-living ecosystem (Poulin, 2007)

Methods

Results

Discussion

Conclusion