Søk
Viser treff 1-10 av 10
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 ...
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 ...
The effect of inter- and intraspecific competition on individual and population niche widths: a four-decade study on two interacting salmonids
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-07-12)
Competition is assumed to shape niche widths, affecting species survival and coexistence. Expectedly, high interspecific competition will reduce population niche widths, whereas high intraspecific competition will do the opposite. Here we test in situ how intra- and interspecific competition affects trophic resource use and the individual and population niche widths of two lacustrine fish species, ...
High parasite diversity in the amphipod Gammarus lacustris in a subarctic lake
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-10-05)
Amphipods are often key species in aquatic food webs due to their functional roles in the ecosystem and as intermediate hosts for trophically transmitted parasites. Amphipods can also host many parasite species, yet few studies address the entire parasite community of a gammarid population, precluding a more dynamic understanding of the food web. We set out to identify and quantify the parasite ...
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 ...
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, ...
Fish culling reduces tapeworm burden in Arctic charr by increasing parasite mortality rather than by reducing density-dependent transmission
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-02-25)
<ol>
<li>Two common <i>Dibothriocephalus</i> (formerly <i>Diphyllobothrium</i>) tapeworm species were significantly reduced by experimental culling of their fish host Arctic charr (<i>Salvelinus alpinus</i>) in a subarctic lake.</li><p>
<p><li>Between 1984 and 1991, funnel traps were used to cull ~35 metric tons of Arctic charr, reducing charr density by ~80%. As charr densities decreased, ...
Seasonal dietary shifts enhance parasite transmission to lake salmonids during ice cover
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-04-08)
Changes in abiotic and biotic factors between seasons in subarctic lake systems are often profound, potentially affecting the community structure and population dynamics of parasites over the annual cycle. However, few winter studies exist and interactions between fish hosts and their parasites are typically confined to snapshot studies restricted to the summer season whereas host‐parasite dynamics ...
Ectoparasites population dynamics are affected by host body size but not host density or water temperature in a 32-year long time series
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-11-22)
Host density, host body size and ambient temperature have all been positively associated
with increases in parasite infection. However, the relative importance of these factors in
shaping long-term parasite population dynamics in wild host populations is unknown
due to the absence of long-term studies. Here, we examine long-term drivers of gill lice
(Copepoda) infections in Arctic charr (Salmonidae) ...