Managing cryptic biodiversity: Fine-scale intralacustrine speciation along a benthic gradient in Alpine whitefish (Coregonus spp.)
Publisher DOI
Abstract
Whitefish (Coregonus spp.) are an important catch for many freshwater fisheries, particularly in Switzerland. In support of this, supplemental stocking of whitefish species
is carried out, despite lacking complete knowledge of the extent, distribution and origin
of whitefish diversity in these lakes, potentially threatening local endemics via artificial
gene flow. Here, we investigate phenotypic and genetic differentiation among
coexisting whitefish species spawning along a depth gradient in a subalpine Swiss lake
to better delineate intralacustrine whitefish biodiversity. We find depth-related
clines in adaptive morphology and in neutral genetic markers. This individual variation is
structured in three distinct clusters with spatial overlap. Individual genetic distances
correlate strongly with differences in growth rate and gill-raker number, consistent
with predictions of isolation-by-adaptation and ecological speciation. Genetic differentiation between species suggests reproductive isolation, despite demographic admixture on spawning grounds. Our results are consistent with clinal speciation
resulting in three species coexisting in close ecological parapatry, one (C. sp. “benthic
intermediate”) being previously unknown. A second unknown species spawning in
close proximity was found to be of potential allochthonous origin. This study highlights
the importance of taxonomically unbiased sampling strategies to both understand
evolutionary mechanisms structuring biodiversity and to better inform conservation and fisheries management.
is carried out, despite lacking complete knowledge of the extent, distribution and origin
of whitefish diversity in these lakes, potentially threatening local endemics via artificial
gene flow. Here, we investigate phenotypic and genetic differentiation among
coexisting whitefish species spawning along a depth gradient in a subalpine Swiss lake
to better delineate intralacustrine whitefish biodiversity. We find depth-related
clines in adaptive morphology and in neutral genetic markers. This individual variation is
structured in three distinct clusters with spatial overlap. Individual genetic distances
correlate strongly with differences in growth rate and gill-raker number, consistent
with predictions of isolation-by-adaptation and ecological speciation. Genetic differentiation between species suggests reproductive isolation, despite demographic admixture on spawning grounds. Our results are consistent with clinal speciation
resulting in three species coexisting in close ecological parapatry, one (C. sp. “benthic
intermediate”) being previously unknown. A second unknown species spawning in
close proximity was found to be of potential allochthonous origin. This study highlights
the importance of taxonomically unbiased sampling strategies to both understand
evolutionary mechanisms structuring biodiversity and to better inform conservation and fisheries management.
Date Issued
2017
Publication Type
Article
Subject(s)
Language(s)
en
Author(s)
Hudson, Alan G. | |
Lundsgaard-Hansen, Baenz | |
Lucek, Kay |
Additional Credits
Journal
Evolutionary applications
Publisher
Wiley
ISSN
1752-4571
Access(Rights)
open.access