Abstract
Ecological opportunities present during colonization of novel environments can drive divergent selection on traits, resulting in specialization of morphs to enhance efficient use of resources. Thus, in an ecologically polymorphic species, differences in resource specialization should be found among morphs, and homogeneity in resource use expected within a morph. Using one of four morphs in Great Bear Lake, we investigate whether specialization of trophic resources among individuals occurs within this single morph, which could indicate a potential for continued divergence. Four distinct dietary patterns of resource use within the lake trout morph were detected from fatty acid composition. Feeding habits of different groups within the morph were not associated with detectable morphological or genetic differentiation, suggesting that behavioral plasticity may have caused the trophic variation within this morph. A low level of genetic differentiation was detected between exceptionally large-sized individuals and other individuals. Investigating a geologically young system that displays high levels of intraspecific diversity and focusing on dietary patterns of resource use variation of individuals suggested that individual specialization can occur within a morph.
List of abbreviations
- BP
- before present
- m
- meter
- mm
- millimeter
- h
- hour
- ca.
- around
- i.e.,
- stands for
- e.g.,
- for example
- NaCl
- Sodium Chloride
- FAME
- fatty acid methyl esters
- H2SO4
- Sulfuric acid
- GC
- Gas chromatographic
- °C
- degree Celsius
- °C/min
- degree Celsius/minutes
- UPGMA
- Unweighted Pair Group Method with Arithmetic Mean
- PCA
- principal component analysis
- PERMANOVA
- Permutational Multivariate Analysis of Variance
- MANOVA
- Multivariate analysis of variance
- SIMPER
- similarity percentage routine
- ANOSIM
- analysis of similarities
- N
- Number of individuals genotyped
- NA
- number of alleles
- HE
- expected heterozygosity
- HO
- observed heterozygosity
- AR
- allelic richness
- PAR
- private allelic richness
- Α
- alpha
- FCA
- Factorial correspondence analysis
- k
- number of alleles
- DAPC
- Discriminant Analysis of Principal Components
- IMP
- Integrated Morphometrics Programs
- CVA
- Canonical Variate Analyses