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Species integrity enhanced by a predation cost to hybrids in the wild

Nilsson, P. Anders LU ; Hulthén, Kaj LU ; Chapman, Ben B. LU ; Hansson, Lars Anders LU ; Brodersen, Jakob LU ; Baktoft, Henrik; Vinterstare, Jerker LU ; Brönmark, Christer LU and Skov, Christian LU (2017) In Biology letters 13(7).
Abstract

Species integrity can be challenged, and even eroded, if closely related species can hybridize and produce fertile offspring of comparable fitness to that of parental species. The maintenance of newly diverged or closely related species therefore hinges on the establishment and effectiveness of pre- and/or post-zygotic reproductive barriers. Ecological selection, including predation, is often presumed to contribute to reduced hybrid fitness, but field evidence for a predation cost to hybridization remains elusive. Here we provide proof-of-concept for predation on hybrids being a postzygotic barrier to gene flow in the wild. Cyprinid fishes commonly produce fertile, viable hybrid offspring and therefore make excellent study organisms to... (More)

Species integrity can be challenged, and even eroded, if closely related species can hybridize and produce fertile offspring of comparable fitness to that of parental species. The maintenance of newly diverged or closely related species therefore hinges on the establishment and effectiveness of pre- and/or post-zygotic reproductive barriers. Ecological selection, including predation, is often presumed to contribute to reduced hybrid fitness, but field evidence for a predation cost to hybridization remains elusive. Here we provide proof-of-concept for predation on hybrids being a postzygotic barrier to gene flow in the wild. Cyprinid fishes commonly produce fertile, viable hybrid offspring and therefore make excellent study organisms to investigate ecological costs to hybrids. We electronically tagged two freshwater cyprinid fish species (roach Rutilus rutilus and bream Abramis brama) and their hybrids in 2005. Tagged fish were returned to their lake of origin, exposing them to natural predation risk from apex avian predators (great cormorant, Phalacrocorax carbo). Scanning for regurgitated tags under cormorant roosts 3-4 years later identified cormorant-killed individual fish and allowed us to directly test for a predation cost to hybrids in the wild. Hybrid individuals were found significantly more susceptible to cormorant predation than individuals from either parental species. Such ecological selection against hybrids contributes to species integrity, and can enhance species diversification.

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Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
cormorant, diversity, evolution, fish, predator–prey
in
Biology letters
volume
13
issue
7
publisher
Royal Society
external identifiers
  • scopus:85038017294
ISSN
1744-9561
DOI
10.1098/rsbl.2017.0208
language
English
LU publication?
yes
id
cdf23fa9-1517-46e6-a04e-1e199d852703
date added to LUP
2018-01-04 13:02:33
date last changed
2018-01-05 03:00:03
@article{cdf23fa9-1517-46e6-a04e-1e199d852703,
  abstract     = {<p>Species integrity can be challenged, and even eroded, if closely related species can hybridize and produce fertile offspring of comparable fitness to that of parental species. The maintenance of newly diverged or closely related species therefore hinges on the establishment and effectiveness of pre- and/or post-zygotic reproductive barriers. Ecological selection, including predation, is often presumed to contribute to reduced hybrid fitness, but field evidence for a predation cost to hybridization remains elusive. Here we provide proof-of-concept for predation on hybrids being a postzygotic barrier to gene flow in the wild. Cyprinid fishes commonly produce fertile, viable hybrid offspring and therefore make excellent study organisms to investigate ecological costs to hybrids. We electronically tagged two freshwater cyprinid fish species (roach Rutilus rutilus and bream Abramis brama) and their hybrids in 2005. Tagged fish were returned to their lake of origin, exposing them to natural predation risk from apex avian predators (great cormorant, Phalacrocorax carbo). Scanning for regurgitated tags under cormorant roosts 3-4 years later identified cormorant-killed individual fish and allowed us to directly test for a predation cost to hybrids in the wild. Hybrid individuals were found significantly more susceptible to cormorant predation than individuals from either parental species. Such ecological selection against hybrids contributes to species integrity, and can enhance species diversification.</p>},
  author       = {Nilsson, P. Anders and Hulthén, Kaj and Chapman, Ben B. and Hansson, Lars Anders and Brodersen, Jakob and Baktoft, Henrik and Vinterstare, Jerker and Brönmark, Christer and Skov, Christian},
  issn         = {1744-9561},
  keyword      = {cormorant,diversity,evolution,fish,predator–prey},
  language     = {eng},
  month        = {07},
  number       = {7},
  publisher    = {Royal Society},
  series       = {Biology letters},
  title        = {Species integrity enhanced by a predation cost to hybrids in the wild},
  url          = {http://dx.doi.org/10.1098/rsbl.2017.0208},
  volume       = {13},
  year         = {2017},
}