Søk
Viser treff 1-10 av 14
Allometric trajectories of body and head morphology in three sympatric Arctic charr (Salvelinus alpinus (L.)) morphs
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-08-08)
A study of body and head development in three sympatric reproductively isolated Arctic charr (Salvelinus alpinus (L.)) morphs from a subarctic lake (Skogsfjordvatn, northern Norway) revealed allometric trajectories that resulted in morphological differences. The three morphs were ecologically assigned to a littoral omnivore, a profundal benthivore and a profundal piscivore, and this was confirmed ...
Parallel and non-parallel morphological divergence among foraging specialists in European whitefish (Coregonus lavaretus)
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013)
Parallel phenotypic evolution occurs when independent populations evolve similar traits in response to similar selective regimes. However, populations inhabiting similar environments also frequently show some phenotypic differences
that result from non-parallel evolution. In this study, we quantified the relative importance of parallel evolution to similar foraging regimes and nonparallel lake-specific ...
Molecular analyses reveal high cryptic diversity of trematodes in a sub-Arctic lake
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-03-14)
To identify trematode diversity and life-cycles in the sub-Arctic Lake Takvatn, Norway, we characterised
120 trematode isolates from mollusc first intermediate hosts, metacercariae from second intermediate
host fishes and invertebrates, and adults from fish and invertebrate definitive hosts, using molecular
techniques. Phylogenies based on nuclear and/or mtDNA revealed high species richness (24 ...
Variation in functional trait composition of benthic invertebrates across depths and seasons in a subarctic lake
(Journal article; Tidsskriftartikkel, 2016-07-01)
Benthic invertebrate communities play a fundamental role in lake ecosystems, and the understanding of how those benthic communities are structured, particularly in terms of the identity and spatiotemporal distribution of their functional traits, is key to our understanding of how lake ecosystems work. In Takvatn, a subarctic lake in northern Norway, we identified the taxonomic and functional identity ...
Ontogenetic dynamics of infection with Diphyllobothrium spp. cestodes in sympatric Arctic charr Salvelinus alpinus (L.) and brown trout Salmo trutta L.
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-12-23)
The trophic niches of Arctic charr and brown trout differ when the species occur in
sympatry
. Their
trophically transmitted parasit
es are expected to reflect these
differences.
Here
, we investigate how the infections
of
Diphyllobothrium dendriticum
and
Diphyllobothrium ditremum
differ between
charr and trout. These tapeworms use
copepods ...
Morphological divergence between three Arctic charr morphs - the significance of the deep-water environment.
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-07-14)
Morphological divergence was evident among three sympatric morphs of Arctic charr (Salvelinus alpinus (L.)) that are ecologically diverged along the shallow-, deep-water resource axis in a subarctic postglacial lake (Norway). The two deep-water (profundal) spawning morphs, a benthivore (PB-morph) and a piscivore (PP-morph), have evolved under identical abiotic conditions with constant low light ...
Sympatric diversification as influenced by ecological opportunity and historical contingency in a young species lineage of whitefish
(Journal article; Tidsskriftartikkel; Peer reviewed, 2010)
In adaptive radiations, ecological opportunity (i.e. niche availability) is considered to be an important driver to increase phenotypic variation, but diversity may also be constrained by historical factors related to colonization events.
How do ecological opportunity and post-glacial colonization history affect the phenotypic diversity in a young species lineage?
We quantified phenotypic diversity ...
Ecological speciation in postglacial European whitefish: rapid adaptive radiations into the littoral, pelagic, and profundal lake habitats
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013)
Understanding how a monophyletic lineage of a species diverges into several adaptive forms has received increased attention in recent years, but the underlying mechanisms in this process are still under debate. Postglacial fishes are
excellent model organisms for exploring this process, especially the initial stages of ecological speciation, as postglacial lakes represent replicated discrete ...
Discrete foraging niches promote ecological, phenotypic, and genetic divergence in sympatric whitefish (Coregonus lavaretus)
(Journal article; Tidsskriftartikkel; Peer reviewed, 2012)
Natural populations often vary in their degree of ecological, morphological and genetic divergence. This variation can be arranged along an ecological speciation continuum of increasingly discrete variation, with high inter-individual variation at one end and well defined species in the other. In postglacial fishes, evolutionary divergence has commonly resulted in the co-occurrence of a pelagic and ...
Long-term responses of zooplankton to invasion by a planktivorous fish in a subarctic watercourse
(Journal article; Tidsskriftartikkel; Peer reviewed, 2008-08-13)
<p>1. Introduced or invading predators may have strong impacts on prey populations of the recipient community mediated by direct and indirect interactions. The long‐term progression of predation effects, covering the invasion and establishment phase of alien predators, however, has rarely been documented.</p>
<p>2. This paper documents the impact of an invasive, specialized planktivorous fish ...