10.5061/DRYAD.7PD82
Quinn, Tom P.
University of Washington
Gowell, Conrad P.
University of Puget Sound
Taylor, Eric B.
University of British Columbia
Data from: Coexistence and origin of trophic ecotypes of pygmy whitefish,
Prosopium coulterii, in southwestern Alaskan lake
Dryad
dataset
2012
Diet Analysis
Prosopium coulterii
Holocene
2012-10-16T17:46:15Z
2012-10-16T17:46:15Z
en
https://doi.org/10.1111/jeb.12011
186843 bytes
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CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
Ecologically, morphologically, and genetically distinct populations within
single taxa often co-exist in postglacial lakes and have provided
important model systems with which to investigate ecological and
evolutionary processes such as niche partitioning and ecological
speciation. Within the Salmonidae, these species complexes have been well
studied, particularly within the Coregonus clupeaformis-C. laveratus (lake
and European whitefish, respectively) group, but the phenomenon has been
less well documented in the other whitefish genera, Prosopium and
Stenodus. Here, we examined the morphology, feeding biology, and genetic
structure of three putative forms of the pygmy whitefish, Prosopium
coulterii, that were first reported from Chignik Lake, southwestern
Alaska, over 40 years ago. Field collections and morphological analyses
resolved a shallow water (< 5 m depth) low gill raker count form
(< 15 first arch gill rakers), a deepwater (> 30 m), low
gill raker form, and a deepwater, high gill raker count (> 15 gill
rakers) form. The two low gill raker count forms fed almost exclusively on
benthic invertebrates (mostly chironomids), while the deepwater, high gill
raker count form fed almost exclusively on zooplankton, differences in
diet that were also reflected in differences both in δ13C and δ15N stable
isotopes. All three forms were characterized by the same major
mitochondrial DNA clade that has been associated with persistence in, and
postglacial dispersal from, a Beringian glacial refugium. Analysis of
variation at nine microsatellite DNA loci indicated low, but significant
differentiation amongst forms, especially between the two low gill raker
count forms and the high gill raker count form. The extent of
differentiation along phenotypic (considerable) and genetic (subtle) axes
amongst the Chignik Lake forms is similar to that found amongst distinct
taxa of Prosopium found in pre-glacial Bear Lake (Utah-Idaho, USA) which
is probably at least ten times older than Chignik Lake. Our analyses
illustrate the potential for the postglacial differentiation in traits
subject to divergent natural selection across variable environments.
microsatellite allele frequenciesMicrosatellite DNA allele frequencies in
base pairsApril113Stomach contentsproportional diet contents (range from 0
- 1.0) for pygmy whitefishdryad.xlsStable isotope dataStable isotope (C,
N) for Chignik Lake pygmy whitefish collected in 2008,
2009dryad.xlsdistancesfromlandmarks_dryadlinear distances from landmark
data for pygmy whitefish collected 2008, 2009 from Chignik Lake
Southwestern Alaska