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Parasitism and the Biodiversity-Functioning Relationship
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-02-15)
Species interactions can influence ecosystem functioning by enhancing or suppressing the activities of species that drive ecosystem processes, or by causing changes in biodiversity. However, one important class of species interactions – parasitism – has been little considered in biodiversity and ecosystem functioning (BD-EF) research. Parasites might increase or decrease ecosystem processes by ...
New parasites and predators follow the introduction of two fish species to a subarctic lake: implications for food-web structure and functioning
(Journal article; Tidsskriftartikkel; Peer reviewed, 2012)
Introduced species can alter the topology of food webs. For instance, an introduction can aid the arrival of free-living consumers using the new species as a resource, while new parasites may also arrive with the introduced species. Food-web responses to species additions can thus be far more complex than anticipated. In a subarctic pelagic food web with free-living and parasitic species, two fish ...
Resource Partitioning in Food, Space and Time between Arctic Charr (Salvelinus alpinus), Brown Trout (Salmo trutta) and European Whitefish (Coregonus lavaretus) at the Southern Edge of Their Continuous Coexistence
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017)
Arctic charr and European whitefish are considered to be strong competitors in lakes, with the latter usually being the superior species. However, high niche plasticity and lake morphometry may suggestively facilitate resource partitioning and coexistence between charr and whitefish. Here, we explore the trophic niche utilization (diet and habitat use) of charr and whitefish co-occurring with brown ...
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 ...
The trade-off between fecundity and egg size in a polymorphic population of Arctic charr (Salvelinus alpinus (L.)) in Skogsfjordvatn, subarctic Norway
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-02-26)
Reproductive traits differ between intralacustrine Arctic charr morphs. Here, we ex
-
amine three sympatric lacustrine Arctic charr morphs with respect to fecundity, egg
size and spawning time/site to assess reproductive investments and trade-
offs, and
possible fitness consequences. The littoral omnivore morph (LO-
morph) utilizes the
upper water for feeding and reproduction and spawn ...
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 ...
Temporal changes and between-host variation in the intestinal parasite community of Arctic charr in a subarctic lake
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-03-16)
The occurrence of trophically transmitted intestinal parasites in Arctic charr was analyzed from data material collected over two decades from Lake Takvatn, northern Norway. The main objectives were to investigate (i) between-year variation in parasite infracommunity composition, (ii) between-host variation in infracommunity composition, and (iii) possible interspecific interaction between parasites. ...
Consistent isotopic differences between Schistocephalus spp. parasites and their stickleback hosts
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-07-23)
Parasite−host systems show markedly variable patterns in isotopic fractionation: parasites can be either depleted or enriched in 15N and 13C as compared to their hosts. However, it remains unknown whether isotopic fractionation patterns are similar in comparable parasite−host systems from markedly different ecosystems. Results of this study show that large-sized Schistocephalus spp. endoparasites ...
Parasite communities of two three-spined stickleback populations in subarctic Norway—effects of a small spatial-scale host introduction
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-01-30)
We compared metazoan parasite communities of an introduced three-spined stickleback (Gasterosteus aculeatus) population with the nearby source population in northern Norway to study differences and clarify if factors controlling parasite dispersal act on a small spatialscale. The two component communities were highly similar. All parasite taxa found in the source population also occurred in the ...