Hostname: page-component-89b8bd64d-ktprf Total loading time: 0 Render date: 2026-05-09T11:38:06.305Z Has data issue: false hasContentIssue false

Mutual dilution of infection by an introduced parasite in native and invasive stream fishes across Hawaii

Published online by Cambridge University Press:  11 July 2016

RODERICK B. GAGNE*
Affiliation:
Department of Ecology and Evolutionary Biology, Tulane University, New Orleans, LA 70118, USA
DAVID C. HEINS
Affiliation:
Department of Ecology and Evolutionary Biology, Tulane University, New Orleans, LA 70118, USA
PETER B. MCINTYRE
Affiliation:
Center for Limnology, University of Wisconsin, Madison, WI 53706, USA
JAMES F. GILLIAM
Affiliation:
Department of Biology, North Carolina State University, Raleigh, NC 27695, USA
MICHAEL J. BLUM
Affiliation:
Department of Ecology and Evolutionary Biology, Tulane University, New Orleans, LA 70118, USA Tulane-Xavier Center for Bioenvironmental Research, Tulane University, 627 Lindy Boggs, New Orleans, LA 70118, USA
*
*Corresponding author. University of Wyoming, 1174 Snowy Range Rd. Laramie, WY 82070, USA. E-mail: rgagne@tulane.edu

Summary

The presence of introduced hosts can increase or decrease infections of co-introduced parasites in native species of conservation concern. In this study, we compared parasite abundance, intensity, and prevalence between native Awaous stamineus and introduced poeciliid fishes by a co-introduced nematode parasite (Camallanus cotti) in 42 watersheds across the Hawaiian Islands. We found that parasite abundance, intensity and prevalence were greater in native than introduced hosts. Parasite abundance, intensity and prevalence within A. stamineus varied between years, which largely reflected a transient spike in infection in three remote watersheds on Molokai. At each site we measured host factors (length, density of native host, density of introduced host) and environmental factors (per cent agricultural and urban land use, water chemistry, watershed area and precipitation) hypothesized to influence C. cotti abundance, intensity and prevalence. Factors associated with parasitism differed between native and introduced hosts. Notably, parasitism of native hosts was higher in streams with lower water quality, whereas parasitism of introduced hosts was lower in streams with lower water quality. We also found that parasite burdens were lower in both native and introduced hosts when coincident. Evidence of a mutual dilution effect indicates that introduced hosts can ameliorate parasitism of native fishes by co-introduced parasites, which raises questions about the value of remediation actions, such as the removal of introduced hosts, in stemming the rise of infectious disease in species of conservation concern.

Information

Type
Research Article
Copyright
Copyright © Cambridge University Press 2016 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Article purchase

Temporarily unavailable

Supplementary material: File

Gagne supplementary material

Figures S1-S3

Download Gagne supplementary material(File)
File 319.1 KB