A survey of salmon gill poxvirus (SGPV) in wild salmonids in Norway          下载免费PDF全文

Å H Garseth  M C Gjessing  T Moldal  A G Gjevre 《Journal of fish diseases》2018,41(1):139-145

In 2016, the Norwegian health monitoring programme for wild salmonids conducted a real‐time PCR‐based screening for salmon gill poxvirus (SGPV) in anadromous Arctic char (Salvelinus alpinus L.), anadromous and non‐anadromous Atlantic salmon (Salmo salar L.) and trout (Salmo trutta L.). SGPV was widely distributed in wild Atlantic salmon returning from marine migration. In addition, characteristic gill lesions, including apoptosis, were detected in this species. A low amount of SGPV DNA, as indicated by high Ct‐values, was detected in anadromous trout, but only in fish cohabiting with SGPV‐positive salmon. SGPV was not detected in trout and salmon from non‐anadromous water courses, and thus seems to be primarily linked to the marine environment. This could indicate that trout are not a natural host for the virus. SGPV was not detected in Arctic char but, due to a low sample size, these results are inconclusive. The use of freshwater from anadromous water sources may constitute a risk of introducing SGPV to aquaculture facilities. Moreover, SGPV‐infected Atlantic salmon farms will hold considerable potential for virus propagation and spillback to wild populations. This interaction should therefore be further investigated.  相似文献   

Little evidence to suggest salmonid freshwater reservoirs of piscine orthoreovirus (PRV)          下载免费PDF全文

Åse Helen Garseth  Eirik Biering 《Journal of fish diseases》2018,41(8):1313-1315

  相似文献   

Low body fat content prior to declining day length in the autumn significantly increased growth and reduced weight dispersion in farmed Atlantic salmon Salmo salar L.          下载免费PDF全文

Kjell‐Arne Rørvik  Jens‐Erik Dessen  Magnus Åsli  Magny S Thomassen  Kjellrun G Hoås  Turid Mørkøre 《Aquaculture Research》2018,49(5):1944-1956

Based on the regulatory effects of body fat on appetite and seasonal variations in fat deposition and growth of Atlantic salmon, the present study tested the hypothesis that body fat content prior to declining day length in the autumn can significantly modulate growth rate. The growth rate of salmon (mean initial body weight, BW = 2.3 kg) with different muscle fat content prior to autumn, subjected to natural photoperiod and temperature, during a 7‐month period (mean final BW = 6.6 kg) was studied. In August, three fish groups (HF, LF and 0.5LF group) with significantly different muscle fat content (HF = 16.4%, LF = 13.2% and 0.5LF = 11.3%), individually marked with PIT‐tag, were mixed into the four net‐pens and fed a standard high‐energy diet until March the following year. The muscle fat content prior to the autumn had a highly significant (p < .0001) effect on growth during the 7‐month main‐dietary period, even after identical fat stores among the groups were restored, indicating a more complex explanation than just a lipostatic regulation mechanism. Mean thermal growth coefficients were HF = 2.9, LF = 3.4 and 0.5 LF = 3.9, resulting in increased final weight gain for LF and 0.5LF of 590 g and 980 g, respectively, compared to the HF group. The LF groups obtained a significantly higher homogeneity in BW and shape than HF‐fed fish in March, optimizing automatic gutting and filleting at slaughter. The improved growth response among the LF groups by reducing lipid levels can potentially be utilized in closed and semi‐closed production units where photoperiod can be manipulated.  相似文献