Browsing Mastergradsoppgaver i fiskehelse by Issue Date
Now showing items 61-72 of 72
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Infeksjon av fiskandmark (Dibothriocephalus ditremus) og måsemark (D. dendriticus) hos ørret (Salmo trutta) i Takvatnet gjennom de siste 20 årene
(Master thesis; Mastergradsoppgave, 2021-06-07)Næringsdyroverførte parasitter er viktige i undersøkelsen av vertens diett og habitat over tid. Dibothriocephalus ditremus (fiskandmark) og D. dendriticus (måsemark) er en av de mest alvorlige parasitter hos fisk i arktiske innsjøer da de kan påføre fiskeverten store konsekvenser og i verste fall død. I Takvatn var disse en av årsakene til at det ble iverksatt et uttynningsfiske av røye på 1980-tallet. ... -
Immunstatus hos fertil og steril laks under sjøfasen - en komparativ oversikt
(Master thesis; Mastergradsoppgave, 2022-05-15)Rømning av oppdrettslaks medfører til uønsket genetisk innblanding i den ville laksebestanden, noe som resulterer i dårligere ytelse og overlevelse hos den ville laksen. I tillegg er kjønnsmodning av oppdrettslaksen et velferdsproblem, da dette medfører en rekke negative effekter for fisken, blant disse redusert vekst, immunrespons og hypo- osmoregulatoriske evner. En mulig løsning på disse problemene ... -
Studiar av B-celler hos laks (Salmo salar) – blir dei aktiverte av TLR-ligandar?
(Master thesis; Mastergradsoppgave, 2022-05-29)Pankreassjukdom, infeksiøs lakseanemi, hjarte- og skjelettmuskelbetennelse og kardiomyopatisyndrom er dei mest utbreidde virussjukdommane i oppdrettsnæringa i Noreg i dag. Sjukdommane har skulda for sterkt nedsett velferd for laksefisk, og store økonomiske tap for oppdretterar langs heile kysten. Vaksinane som blir nytta mot virus i dag har ikkje tilfredsstillande effekt, då vaksinert fisk framleis ... -
Studier av B-celler hos laks (Salmo salar) - Aktiveres de av TLR-ligander?
(Master thesis; Mastergradsoppgave, 2022-05-29)Virussykdommer hos atlantisk laks (Salmo salar) er en av de største utfordringene i norsk akvakulturindustri, og i tillegg til store økonomiske tap for næringa, fører virussykdommene også med seg store fiskevelferdsmessige problemer. Virusvaksinene som er tilgjengelig på det norske markedet i dag har vist å gi begrenset grad av beskyttelse, og velferdsmessige bekymringer er knyttet opp mot bivirkningene ... -
Effects of acute and chronic handling stress on antiviral responses in Atlantic salmon (Salmo salar) red blood cells and testing of stress target genes
(Master thesis; Mastergradsoppgave, 2023-05-13)The salmonids in today’s Norwegian aquaculture are exposed to many stressors, like suboptimal water quality, crowding and handling. This project focuses on red blood cell (RBCs) function in Atlantic salmon and how cellular responses are affected by stress. Since fish RBCs are nucleated and can change their gene expression, one of the main goals of this thesis is to better understand how the ... -
Whole genome sequencing reveals development of structured salmon lice (Lepeophtheirus salmonis, Krøyer, 1838) populations among aquaculture net pens through production
(Master thesis; Mastergradsoppgave, 2023-05-15)Salmon louse, (Lepeophtheirus salmonis, Krøyer, 1838), is an ectoparasite that causes multiple health and economic problems in the farming of Atlantic salmon (Salmo salar L.), but also threatens wild salmonid species. The industry is struggling to identify proper measures for limiting lice infections, and to identify effective delousing treatments. One of the major production and management challenges, ... -
Impacts of climate-related temperature stress on Atlantic salmon (Salmo salar L.) gills
(Master thesis; Mastergradsoppgave, 2023-05-15)Constantly increasing water temperatures caused by climate change, can lead to major consequences for the welfare of farmed fish. The interactions between the expected changes and the fish physiology are still not understood, in specific how the changing environment may affect the fish's health, and how this may impact aquaculture production in general. The fish's gill health can be used as an ... -
The effect of climate related stressors on liver in Atlantic salmon (Salmo salar)
(Master thesis; Mastergradsoppgave, 2023-05-15)Climate change impacts the average temperature in the world’s oceans, as well as other environmental parameters, such as oxygen levels. These changes are threatening and challenging animals living there, including farmed species. In this trial Atlantic salmon (Salmo salar) were exposed to fluctuating temperature (12-17C) as a single stressor, and in combination with lowered level of dissolved oxygen ... -
Impact of temperature-dependent developmental plasticity on immune response and cardiac health to Yersinia ruckeri infection, in Atlantic salmon parr
(Master thesis; Mastergradsoppgave, 2023-05-15)Heart injuries and diseases are one of the largest challenges in Atlantic salmon aquaculture. Presently, salmon experience intensive farming conditions and feeding regimes, and different viral and bacterial pathogens flourish and create cardiac health risks. Many have suggested how early life history plays a greater role in performance than previously assumed. The RCN-NFR funded project COOLFISH ... -
Nonclassical MHC class I L-lineage genes in Atlantic Salmon (Salmo salar L.): An investigation into transcriptional induction and cell type-specific expression patterns of different L-lineage subgroups
(Master thesis; Mastergradsoppgave, 2023-05-15)The world's population is growing, and so is the world's food demand, underpinning the need for sustainable food production. Over the last few decades, Norwegian aquaculture production of Atlantic Salmon (Salmo Salar L.) and rainbow trout (Oncorhynchus mykiss) expanded rapidly. Unfortunately, today’s fish health situation is challenging due to virus infections, among other reasons. Today's virus ... -
Seasonal dynamics of four cryptic species of Crepidostomum spp. in a subarctic lake in Northern Norway
(Master thesis; Mastergradsoppgave, 2023-05-16)The function of parasites in ecosystems is often overlooked, and there is a general lack of knowledge about parasite biodiversity down to species levels, especially for cryptic species. This study looks at the seasonal dynamics of four cryptic species of the trematode Crepidostomum spp. in Lake Takvatn, Northern Norway. Samples were collected between June 2017 and May 2018, and a total of 560 ... -
Evaluation of ozone and peracetic acid use during a Yersinia ruckeri challenge in Atlantic salmon (Salmo salar) freshwater recirculating aquaculture systems
(Master thesis; Mastergradsoppgave, 2023-05-16)Yersinia ruckeri (Y. ruckeri) the causative agent of Enteric red-mouth disease (ERM), a serious septicemic bacterial disease of salmonid fish, poses a significant challenge in salmon production. With the emergence of recirculating aquaculture system (RAS) in Norway, new biological challenges in relation to infectious disease outbreaks have arisen. There is a gap in knowledge on how potential ...