Search
Now showing items 1-10 of 16
Røye som langtidsvert og smittereservoar for Gyrodactylus salaris i Skibotnelva i Troms
(Research report; Forskningsrapport, 2005-03)
Skibotnelva i Troms var lenge det eneste vassdraget i våre to nordligste fylker med infeksjon av fiskeparasitten Gyrodactylus salaris. Parasitten ble første gang påvist i 1979, og to rotenonbehandlinger i den lakseførende delen (i 1988 og 1995) har vært mislykkede. Di-rektoratet for naturforvaltning vurderer bygging av langtidssperre som et av flere aktuelle utryddingstiltak i Skibotnelva. Imidlertid ...
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 ...
Takvatnprosjektet - Forskning og kultivering av en overbefolka røyeberstand
(Research report; Forskningsrapport, 2015)
Overbefolka fiskebestander er et stort problem i mange av våre innsjøer. Det typiske
kjennetegnet er en stor tetthet av gammel, småvokst og mager fisk, gjerne med en
høy infeksjon av parasitter. Hardt uttynningsfiske har vært foreslått som et mulig
botemiddel, men selv om det har vært gjort mange forsøk på å komme problemet til
livs, er det få som har lyktes. Denne rapporten ...
Transmission dynamics of the monogenean Gyrodactylus salaris under seminatural conditions
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014-07-12)
Tracking individual variation in the dynamics of parasite infections in wild populations is often complicated by lack of knowledge of the epidemiological history of hosts. Whereas the dynamics and development of Gyrodactylus salaris Malmberg, 1957, on Atlantic salmon, Salmo salar L., are known from laboratory studies, knowledge about infection development on individual wild fishes is currently sparse. ...
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 ...