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Genetic Structure of Pacific Trout at the Extreme Southern End of Their Native Range.

Abadía-Cardoso A, Garza JC, Mayden RL, García de León FJ - PLoS ONE (2015)

Bottom Line: We confirmed substantial genetic diversity and extremely strong genetic differentiation present in the Mexican trout complex, not only between basins but also between some locations within basins, with at least four species-level taxa present.We also revealed significant divergence between Mexican trout and other trout species and found that introgression from non-native rainbow trout is present but limited, and that the genetic integrity of native trout is still maintained in most locations.This information will help to guide effective conservation strategies for this important group of fishes.

View Article: PubMed Central - PubMed

Affiliation: Fisheries Ecology Division, Southwest Fisheries Science Center, National Marine Fisheries Service, Santa Cruz, California, United States of America; Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, California, United States of America.

ABSTRACT
Salmonid fishes are cold water piscivores with a native distribution spanning nearly the entire temperate and subarctic northern hemisphere. Trout in the genus Oncorhynchus are the most widespread salmonid fishes and are among the most important fish species in the world, due to their extensive use in aquaculture and valuable fisheries. Trout that inhabit northwestern Mexico are the southernmost native salmonid populations in the world, and the least studied in North America. They are unfortunately also facing threats to their continued existence. Previous work has described one endemic species, the Mexican golden trout (O. chrysogaster), and one endemic subspecies, Nelson's trout (O. mykiss nelsoni), in Mexico, but previous work indicated that there is vastly more biodiversity in this group than formally described. Here we conducted a comprehensive genetic analysis of this important group of fishes using novel genetic markers and techniques to elucidate the biodiversity of trout inhabiting northwestern Mexico, examine genetic population structure of Mexican trout and their relationships to other species of Pacific trout, and measure introgression from non-native hatchery rainbow trout. We confirmed substantial genetic diversity and extremely strong genetic differentiation present in the Mexican trout complex, not only between basins but also between some locations within basins, with at least four species-level taxa present. We also revealed significant divergence between Mexican trout and other trout species and found that introgression from non-native rainbow trout is present but limited, and that the genetic integrity of native trout is still maintained in most locations. This information will help to guide effective conservation strategies for this important group of fishes.

No MeSH data available.


Related in: MedlinePlus

Unrooted neighbor-joining dendrograms.a) using data from both 12 microsatellites and 85 SNPs combined and b) using data from 12 microsatellite markers. The dendrogram was constructed with pairwise chord distances and bootstrap values are from 1,000 distance matrices constructed from bootstrap samples of the data from 18 O. mykiss, 19 NSMO, 10 O. chrysogaster, and 12 SSMO natural-origin populations, four O. clarkii subspecies, and five Mexican and four U.S. hatchery stocks. Bootstrap support > 50% percent is indicated for Mexican trout groupings (for O. mykiss see Garza et al. 2014). DPS affiliations of California O. mykiss populations (creeks) are highlighted in colors. Mexican natural-origin populations are indicated with branches and names colored.
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pone.0141775.g006: Unrooted neighbor-joining dendrograms.a) using data from both 12 microsatellites and 85 SNPs combined and b) using data from 12 microsatellite markers. The dendrogram was constructed with pairwise chord distances and bootstrap values are from 1,000 distance matrices constructed from bootstrap samples of the data from 18 O. mykiss, 19 NSMO, 10 O. chrysogaster, and 12 SSMO natural-origin populations, four O. clarkii subspecies, and five Mexican and four U.S. hatchery stocks. Bootstrap support > 50% percent is indicated for Mexican trout groupings (for O. mykiss see Garza et al. 2014). DPS affiliations of California O. mykiss populations (creeks) are highlighted in colors. Mexican natural-origin populations are indicated with branches and names colored.

Mentions: Topologies of the two unrooted dendrograms (Fig 6) were generally concordant, with the exception of the populations from the southern ríos Presidio and Baluarte that clustered within the O. mykiss lineage on the combined tree (Fig 6a), but formed a separate group (but with low bootstrap support) on the microsatellite tree (Fig 6b).


Genetic Structure of Pacific Trout at the Extreme Southern End of Their Native Range.

Abadía-Cardoso A, Garza JC, Mayden RL, García de León FJ - PLoS ONE (2015)

Unrooted neighbor-joining dendrograms.a) using data from both 12 microsatellites and 85 SNPs combined and b) using data from 12 microsatellite markers. The dendrogram was constructed with pairwise chord distances and bootstrap values are from 1,000 distance matrices constructed from bootstrap samples of the data from 18 O. mykiss, 19 NSMO, 10 O. chrysogaster, and 12 SSMO natural-origin populations, four O. clarkii subspecies, and five Mexican and four U.S. hatchery stocks. Bootstrap support > 50% percent is indicated for Mexican trout groupings (for O. mykiss see Garza et al. 2014). DPS affiliations of California O. mykiss populations (creeks) are highlighted in colors. Mexican natural-origin populations are indicated with branches and names colored.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4624944&req=5

pone.0141775.g006: Unrooted neighbor-joining dendrograms.a) using data from both 12 microsatellites and 85 SNPs combined and b) using data from 12 microsatellite markers. The dendrogram was constructed with pairwise chord distances and bootstrap values are from 1,000 distance matrices constructed from bootstrap samples of the data from 18 O. mykiss, 19 NSMO, 10 O. chrysogaster, and 12 SSMO natural-origin populations, four O. clarkii subspecies, and five Mexican and four U.S. hatchery stocks. Bootstrap support > 50% percent is indicated for Mexican trout groupings (for O. mykiss see Garza et al. 2014). DPS affiliations of California O. mykiss populations (creeks) are highlighted in colors. Mexican natural-origin populations are indicated with branches and names colored.
Mentions: Topologies of the two unrooted dendrograms (Fig 6) were generally concordant, with the exception of the populations from the southern ríos Presidio and Baluarte that clustered within the O. mykiss lineage on the combined tree (Fig 6a), but formed a separate group (but with low bootstrap support) on the microsatellite tree (Fig 6b).

Bottom Line: We confirmed substantial genetic diversity and extremely strong genetic differentiation present in the Mexican trout complex, not only between basins but also between some locations within basins, with at least four species-level taxa present.We also revealed significant divergence between Mexican trout and other trout species and found that introgression from non-native rainbow trout is present but limited, and that the genetic integrity of native trout is still maintained in most locations.This information will help to guide effective conservation strategies for this important group of fishes.

View Article: PubMed Central - PubMed

Affiliation: Fisheries Ecology Division, Southwest Fisheries Science Center, National Marine Fisheries Service, Santa Cruz, California, United States of America; Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, California, United States of America.

ABSTRACT
Salmonid fishes are cold water piscivores with a native distribution spanning nearly the entire temperate and subarctic northern hemisphere. Trout in the genus Oncorhynchus are the most widespread salmonid fishes and are among the most important fish species in the world, due to their extensive use in aquaculture and valuable fisheries. Trout that inhabit northwestern Mexico are the southernmost native salmonid populations in the world, and the least studied in North America. They are unfortunately also facing threats to their continued existence. Previous work has described one endemic species, the Mexican golden trout (O. chrysogaster), and one endemic subspecies, Nelson's trout (O. mykiss nelsoni), in Mexico, but previous work indicated that there is vastly more biodiversity in this group than formally described. Here we conducted a comprehensive genetic analysis of this important group of fishes using novel genetic markers and techniques to elucidate the biodiversity of trout inhabiting northwestern Mexico, examine genetic population structure of Mexican trout and their relationships to other species of Pacific trout, and measure introgression from non-native hatchery rainbow trout. We confirmed substantial genetic diversity and extremely strong genetic differentiation present in the Mexican trout complex, not only between basins but also between some locations within basins, with at least four species-level taxa present. We also revealed significant divergence between Mexican trout and other trout species and found that introgression from non-native rainbow trout is present but limited, and that the genetic integrity of native trout is still maintained in most locations. This information will help to guide effective conservation strategies for this important group of fishes.

No MeSH data available.


Related in: MedlinePlus