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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 ...
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. ...
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 ...
Cercarial behaviour alters the consumer functional response of three-spined sticklebacks
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-01-22)
<ol>
<li>Free-living parasite life stages may contribute substantially to ecosystem biomass and thus represent a significant source of energy flow when consumed by non-host organisms. However, ambient temperature and the predator's own infection status may modulate consumption rates towards parasite prey.</li>
<li>We investigated the combined effects of temperature and predator infection status ...
Taxa-specific activity loss and mortality patterns in freshwater trematode cercariae under subarctic conditions
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-11-11)
Cercarial activity and survival are crucial traits for the transmission of trematodes. Temperature is particularly important, as faster depletion of limited cercarial energy reserves occurs at high temperatures. Seasonal climate conditions in high latitude regions may be challenging to complete trematode life cycle during the 6-month ice-free period, but temperature effects on the activity and ...
Temperature does not influence functional response of amphipods consuming different trematode prey
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-08-26)
Direct consumption on free-living cercariae stages of trematodes by non-host organisms interferes with trematode transmission and leads to reduced infections in the next suitable hosts. Consumer functional responses provide a useful tool to examine relationships between consumption rates and ecologically relevant prey densities, whilst also accounting for abiotic factors that likely influence ...
Long-term ecological studies in northern lakes – challenges, experiences, and accomplishments
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-08-15)
We review three long‐term research programs performed over the last four decades on the ecology and management of oligotrophic lake systems with different fish communities at 69° N in Norway. Through whole‐lake perturbation experiments, intensive culling of stunted fish removed 35 tons (1984–1991) of Arctic charr <i>Salvelinus alpinus</i> in Takvatn (15 km<sup>2</sup>) and 153 tons (1981–1983, ...