Epigenetic adaptation in salmon lice
Purpose: To use delousing strategies optimally it is necessary to consider the duration of expected effectiveness and potential resistance development in lice. Inheritable resistance need not be genetically defined, however, and traits based on non-genetic inheritance are more dynamic and may be lost after a few generations (e.g. Rechavi et al. 2011, Jablonka 2017). This has a large impact on the sustainability of a preventive strategy; if resilience is genetic, and hence quite permanent, a treatment will likely permanently lose its effect over time. In contrast, if resilience is transient and reversible, as is expected for epigenetic traits, it may be overcome by management procedures and the treatment will retain its efficacy. This experiment will investigate the involvement of epigenetic inheritance in variation governing low salinity and high temperature tolerance in salmon lice. The experiment will further elucidate the potential heritability of these tolerance mechanisms, and whether tolerance to one of these factors is linked to the other. The experimental treatments will be applied to the salmon louse larvae before infecting the fish, and the fish will therefore not be exposed to experimental tratments,
Negative impact: The experiments involve infestation of fish with salmon lice. The infection causes irritation to the fish during the lice infection procedure. Experience from earlier infestations studies indicate that the intended infestations levels (0,1 lice/gr.) do not cause continuous irritation to the fish. Sampling of lice eggs is done under sedation. Termination of fish by an overdose of sedative represents a humane experimental endpoint.
Expected benefit: Optimal use of delousing strategies is essential for managing the salmon lice burden, and hence benefit the close to 1000 million wild and farmed salmonid fishes that spend most or parts of their life in the marine environment. Understanding resilience mechanisms and dynamics in salmon lice, in turn, is of paramount importance for optimal use of delousing strategies. This experiment will investigate resilience mechanisms and produce advise to optimal use of delousing methods through a FHF project and the associated community outreach.
Experimental animals: The experiment involves infecting 72 salmon in single fish tanks (Salmo salar, 200-400 gr.) with salmon louse (Lepeopththeirus salmonis) copepodids with a target infection of 0,1 lice pr. gr. fish. For the individual fish he experiment will last for up to 3 months from infection to termination. During this period the fish we experience discomfort during the infection, sampling and termination.
3R: There is no replacement available for the maintenance of salmon lice other than salmonid fishes. In accordance with the 3R doctrine we use single fish in single fish tanks to increase experimental resolution and minimize the number of fish involved in the project.
Negative impact: The experiments involve infestation of fish with salmon lice. The infection causes irritation to the fish during the lice infection procedure. Experience from earlier infestations studies indicate that the intended infestations levels (0,1 lice/gr.) do not cause continuous irritation to the fish. Sampling of lice eggs is done under sedation. Termination of fish by an overdose of sedative represents a humane experimental endpoint.
Expected benefit: Optimal use of delousing strategies is essential for managing the salmon lice burden, and hence benefit the close to 1000 million wild and farmed salmonid fishes that spend most or parts of their life in the marine environment. Understanding resilience mechanisms and dynamics in salmon lice, in turn, is of paramount importance for optimal use of delousing strategies. This experiment will investigate resilience mechanisms and produce advise to optimal use of delousing methods through a FHF project and the associated community outreach.
Experimental animals: The experiment involves infecting 72 salmon in single fish tanks (Salmo salar, 200-400 gr.) with salmon louse (Lepeopththeirus salmonis) copepodids with a target infection of 0,1 lice pr. gr. fish. For the individual fish he experiment will last for up to 3 months from infection to termination. During this period the fish we experience discomfort during the infection, sampling and termination.
3R: There is no replacement available for the maintenance of salmon lice other than salmonid fishes. In accordance with the 3R doctrine we use single fish in single fish tanks to increase experimental resolution and minimize the number of fish involved in the project.