Barriers to hybridisation and their conservation implications for a highly threatened Australian fish species

Karl G. Moy, Peter J. Unmack, Mark Lintermans, Richard P. Duncan, Culum Brown

Research output: Contribution to journalArticleResearchpeer-review

Abstract

Hybridisation and introgression are natural phenomena that may lead to the transfer of adaptive alleles from one species to another and increased species diversity. At the same time, hybridisation and subsequent introgression threaten many species world-wide through the loss of genetic and species diversity. In Australia, introgressive hybridisation between native and alien species has not typically been considered a significant threat to native biodiversity because of the taxonomic distance between native and alien biota. However, many native fish have been introduced outside their natural range. Recently, four taxa in the genus Melanotaenia have been nationally listed as threatened due to introgressive hybridisation with introduced Melanotaenia splendida. We examined pre- and post-zygotic barriers to hybridisation between M. splendida and one of these threatened taxa—Running River rainbowfish (RRR)—to assess the potential for hybridisation to occur. We used dichotomous mate choice experiments to examine pre-zygotic barriers and mating experiments to examine post-zygotic barriers. Size was not a significant predictor of the proportion of time subjects spent with a potential mate, nor was there any significant difference in the amount of time subjects spent with potential mates of their own or the opposite species. Eggs from hybrid pairings with female RRR had a slightly higher hatching rate than those from hybrid pairings with female M. splendida, but neither were significantly different from intraspecies crosses. We could not identify any definite barriers to hybridisation, demonstrating that the introduction of “native” fish species outside their natural range poses a higher risk of hybridisation than previously thought. We call for better education around the consequences of moving “native” fish and the development of rapid response plans to deal with recently established alien populations of Australian fish species in order to prevent future extinctions due to introgressive hybridisation.

LanguageEnglish
Pages142-152
Number of pages11
JournalEthology
Volume125
Issue number3
Early online date14 Jan 2019
DOIs
Publication statusPublished - Mar 2019

Fingerprint

hybridization
introgression
fish
species diversity
rivers
mating behavior
education
indigenous species
extinction
hatching
mate choice
biodiversity
alleles
introduced species
river
native species
genetic variation
biota
organisms
allele

Keywords

  • behaviour
  • introgression
  • invasive species
  • mate choice
  • post-zygotic
  • pre-zygotic

Cite this

Moy, Karl G. ; Unmack, Peter J. ; Lintermans, Mark ; Duncan, Richard P. ; Brown, Culum. / Barriers to hybridisation and their conservation implications for a highly threatened Australian fish species. In: Ethology. 2019 ; Vol. 125, No. 3. pp. 142-152.
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Barriers to hybridisation and their conservation implications for a highly threatened Australian fish species. / Moy, Karl G.; Unmack, Peter J.; Lintermans, Mark; Duncan, Richard P.; Brown, Culum.

In: Ethology, Vol. 125, No. 3, 03.2019, p. 142-152.

Research output: Contribution to journalArticleResearchpeer-review

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