The invasion of Patagonia by Chinook salmon ( Oncorhynchus tshawytscha ): inferences from mitochondrial DNA patterns

RIVA-ROSSI, CARLA; PASCUAL, MIGUEL ALBERTO; AEDO MARCHANT, E; BASSO, N; CIANCIO, JAVIER; MEZGA, B; FERNANDEZ, DANIEL ALFREDO; ERNS-ELIZALDE, B

GENETICA

SPRINGER

Lugar: Berlin; Año: 2012 vol. 140 p. 439 - 453

0016-6707

The Chinook salmon Oncorhynchus tshawyts-cha , which was introduced deliberately in Chile four dec-ades ago for sport fishing and aquaculture, represents a rareexample of a successful translocation of an anadromousPacific salmon into the southern Hemisphere, offering aunique opportunity to examine the role of introductionhistory and genetic variability in invasion success. We usedhistorical information and mitochondrial displacement loopsequences (D-loop) from seven colonized sites in Chile andArgentina and from native and naturalized Chinook salmonpopulations to determine population sources and to exam-ine levels of genetic diversity associated with the invasion. The analysis revealed that the Chinook salmon invasion inPatagonia originated from multiple population sourcesfrom northwestern North America and New Zealand, andadmixed in the invaded range generating geneticallydiverse populations. Genetic analyses further indicated thatthe colonization of new populations ahead of the invasionfront appear to have occurred by noncontiguous dispersal.Dispersal patterns coincided with ocean circulation pat-terns dominated by the West Wind Drift and the Cape HornCurrents. We conclude that admixture following multipleintroductions, as well as long-distance dispersal events mayhave facilitated the successful invasion and rapid dispersalof Chinook salmon into Patagonia.