Comparative study of susceptibility to infectious salmon anemia virus in three salmonid species
An important aim of the current study is to compare the susceptibility of Arctic char, trout and Atlantic salmon juveniles (fry, parr and post-smolt) to infection with ISAV. While salmon is highly susceptible to the virus, both char and trout is expected to be less so, though age may likely be an important factor for the ability to withstand infection. Important aspects of the ISA-virus virulence and capacity to spread between the fish will be compared between the three species. In salmon, the main route of entry is known to be via gill epithelium but the relative importance of tissue port may vary with age and between species. The ability of the ISA-virus to spread via water depends on viral shedding to the water, where both route and rate may vary with age and species, and accordingly needs to be investigated.
As part of its social assignment, IMR has an obligation to evaluate the risk of disease transmission between aquaculture and wild fish stocks. The proposed experiment will address a considerable gap in our knowledge about the relative susceptibility of salmonid species naturally present in the vicinity of aquacultural plants. The outcome of the experiment will have impact both for regulatory bodies and for the scientific society and we expect several peer-reviewed scientific papers to be made based on the study.
The study is divided to two separate experiments. In experiment 1, the susceptibility and infectiousness of fry of Atlantic salmon (Salmo salar), Arctic char (Salvelinus alpinus) and trout (Salmo trutta), respectiviely, will be studied. In experiment 2, the susceptibility of post-smolts of Atlantic salmon (Salmo salar), Arctic char (Salvelinus alpinus) and trout (Salmo trutta), respectiviely, will be studied. In both experiments, a well established cohabitation challenge model will e used for this purpose.
The impact on the experimental fish is expected to be severe, with development of clinical ISA and acute mortality in shedder and cohabitant salmon. The clipping of adipose fins will cause moderate effect.
Since susceptibility to infection and the resulting pathogenesis happens at the organismal level, these challenge experiments cannot currently be substituted by less severe methods such as use of in vitro models. The best way to meet the 3R requirements is hence to balance the use of experimental fish against the ‘certainty’ of obtaining important and meaningful results. Secondly, to perform as many valuable analyses as possible to gain as much new knowledge as is within reach from the resources available. The total number of salmon used in this experiment is 17907.
As part of its social assignment, IMR has an obligation to evaluate the risk of disease transmission between aquaculture and wild fish stocks. The proposed experiment will address a considerable gap in our knowledge about the relative susceptibility of salmonid species naturally present in the vicinity of aquacultural plants. The outcome of the experiment will have impact both for regulatory bodies and for the scientific society and we expect several peer-reviewed scientific papers to be made based on the study.
The study is divided to two separate experiments. In experiment 1, the susceptibility and infectiousness of fry of Atlantic salmon (Salmo salar), Arctic char (Salvelinus alpinus) and trout (Salmo trutta), respectiviely, will be studied. In experiment 2, the susceptibility of post-smolts of Atlantic salmon (Salmo salar), Arctic char (Salvelinus alpinus) and trout (Salmo trutta), respectiviely, will be studied. In both experiments, a well established cohabitation challenge model will e used for this purpose.
The impact on the experimental fish is expected to be severe, with development of clinical ISA and acute mortality in shedder and cohabitant salmon. The clipping of adipose fins will cause moderate effect.
Since susceptibility to infection and the resulting pathogenesis happens at the organismal level, these challenge experiments cannot currently be substituted by less severe methods such as use of in vitro models. The best way to meet the 3R requirements is hence to balance the use of experimental fish against the ‘certainty’ of obtaining important and meaningful results. Secondly, to perform as many valuable analyses as possible to gain as much new knowledge as is within reach from the resources available. The total number of salmon used in this experiment is 17907.