The new data on the parasites fauna of the Lake Kronotskoe sympatric charr forms (genus Salvelinus (Nilsson) Richardson, 1836) is presented. Parasites fauna of Bigmouth and Smallmouth charr forms are described for the first time. The information about Longhead charr, Nosed charr and White charr parasites is added. 29 species of parasites from 9 classes were found: Oligohymenophorea, Myxosporåà, ...

The eye represents an immune privileged organ where parasites can escape host reactions. This study provides the first systematic evidence of the pathology associated with <i>Diplostomum</i> sp. infection in the eye retina of fish (i.e. Arctic charr). Histological sections showed that the trematodes caused mechanical disengagement between the retinal pigmentary epithelium and the neurosensory retina, ...

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 ...

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 ...

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 ...

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 ...

From 2011 to 2013, anadromous brown trout Salmo trutta (213−730 mm, total body length, LT) were collected during or shortly after their marine feeding migration at 7 different localities in central Norway. The mean volume of stomach content (%) of marine fish prey eaten by S. trutta captured in marine waters varied from 34 to 89%. There was a high prevalence (67−100%) for parasite groups potentially ...

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 ...

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 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 ...