Galaxias maculatus: An explanation of its biogeography

Tim M. Berra*, L. E L M Crowley, Walter Ivantsoff, Paul A. Fuerst

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

59 Citations (Scopus)

Abstract

Galaxias maculatus is a small diadromous fish found in Australia, New Zealand, South America and on some oceanic islands. Two hypotheses have been advanced to explain this widespread, disjunct distribution. McDowall promoted dispersal through the sea of salt-tolerant juveniles but Rosen and others claimed that the distribution reflected the break-up of Gondwana and subsequent drift of the southern continents. Allozyme electrophoresis of muscle extracts of specimens of Galaxias maculatus from eastern and western Australia, New Zealand and Chile was used to test the hypothesis that populations of G. maculatus from the western Pacific and the eastern Pacific do not differ genetically. F(ST) based on allele frequencies and genotypes was 0.14, suggesting only minor differentiation between eastern and western Pacific populations. Minor differentiation in allele frequency existed at some loci, but no fixation of alternative alleles has occurred. The populations examined appear to be part of the same gene pool, indicating that gene flow via dispersal through the sea occurs today. It is unlikely that South American and Australasian populations would be conspecific if they have exchanged no migrants since the break-up of Gondwana at the end of the Mesozoic.

Original languageEnglish
Pages (from-to)845-849
Number of pages5
JournalMarine and Freshwater Research
Volume47
Issue number6
Publication statusPublished - 1996

Fingerprint Dive into the research topics of 'Galaxias maculatus: An explanation of its biogeography'. Together they form a unique fingerprint.

Cite this