Search
Now showing items 11-20 of 55
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 ...
Effects of fish species composition on Diphyllobothrium spp. infections in subarctic brown trout - is three-spined stickleback a key species?
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-04-25)
Subarctic populations of brown trout (Salmo trutta) are often heavily infected with cestodes of the genus Diphyllobothrium, assumedly because of their piscivorous behavior. This study explores possible associations between availability of fish prey and Diphyllobothrium spp. infections in lacustrine trout populations. Trout in i) allopatry (group T); ii) sympatry with Arctic charr (Salvelinus alpinus) ...
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 ...
A simplified method to estimate Diphyllobothrium spp. infection in salmonids
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-10-13)
Some fish parasites constitute severe management
problems as they may cause mortality of their fish
host or are important zoonoses of humans. Parasite
assessments are therefore critical to keep track
of infections. If conventional sampling techniques
can be simplified, parasite assessments might be
easier to obtain, less time-consuming and more
extensive. In this study, we compare the ...
Lake size and fish diversity determine resource use and trophic position of a top predator in high-latitude lakes
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-03-23)
Prey preference of top predators and energy flow across habitat boundaries are of fundamental importance for structure and function of aquatic and terrestrial ecosystems, as they may have strong effects on production, species diversity, and food-web stability. In lakes, littoral and pelagic food-web compartments are typically coupled and controlled by generalist fish top predators. However, the ...
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 ...
Invader population speeds up life history during colonization
(Journal article; Tidsskriftartikkel; Peer reviewed, 2012)
We explore the long-term developments in population biology and life history during the invasion and establishment of the fish species vendace Coregonus albula in a subarctic watercourse by comparing life-history traits and molecular genetic estimates between the source and the colonist population. The two populations exhibited highly contrasting life-history strategies. Relative to the source ...
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 ...