Behavioral breeding experiment
1 Purpose
In Atlantic salmon, sexual maturity is controlled by a single locus, vgll3, that explains up to 40% of the variation in the time spent at sea before returning to freshwater to spawn. Females mature later than males favoring the late allele (L), resulting in larger sizes and higher reproductive success. Males return to spawn at a younger age thus favoring the early (E) allele. The difference in the two reproductive strategies results in intralocus sexual conflict at the vgll3 locus where one sex favors the opposite allele favored by the other sex at a particular locus. Through a breeding behavior experiment, we aim to measure courtship and aggressive (agonistic) behaviors of breeding adult Atlantic salmon and measure reproductive fitness of adults related to vgll3 genotypes. This experiment will be carried out at the Norwegian Institute for Nature Research (NINA) research station, Ims Norway.
2 Distress
Fish used in the behavioral breeding experiment will be anesthetized prior to handling during weighing, measuring, and tagging procedures and allowed ample time for recovery to minimize distress. Fish will be removed from the breeding experiment if signs of distress are apparent and euthanized.
3 Expected benefit
This experiment will show how traits associated with different vgll3 genotypes influence reproductive decisions and influence the quality and quantity of offspring. This research is important because it will link phenotypic traits, vgll3 genotypes and reproductive fitness in order to understand how genetic variation and sexual conflict at this locus is maintained in Atlantic salmon. This research will aid fisheries management and conservation efforts by gaining insight into the reproductive decisions of this important commercial food and recreational angling fish.
4 Number of animals, and what kind
152 adult Atlantic salmon (Salmo salar) + 5000 swim-up fry . Adults used in the experiment are bred from wild-caught ‘living gene bank’ parents Atlantic salmon (hatching dates, 2015-2017) and released as pre-smolt parr into the Imsa River. Fish are recaptured (Sept-November) when returning to spawn at the Imsa River fish trap. These fish are usually have spent 1-2 years at sea (seawinters). Recaptured fish are held at the Ims station, separated by sex, and maintained for breeding purposes unrelated to this experiment by Ims staff. 96 adults (48 males, 48 females) will be used in the breeding experiment and will be euthanized and dissected afterward for gene expression studies. An additional 24 fish (12 males, 12 females) will be held at Ims to use as alternates in case fish need to be replaced in the experiment. 32 additional fish (16 males, 16 females) will have their gametes collected for fertilization experiments and released in the wild. All fish not used in the breeding experiment will be returned to the wild after the experiment is over. We estimate approximately 5000 offspring (swim-up fry stage, ~1 month after hatching) resulting from spawning which will be collected for genetics/parentage analysis the following spring.
In Atlantic salmon, sexual maturity is controlled by a single locus, vgll3, that explains up to 40% of the variation in the time spent at sea before returning to freshwater to spawn. Females mature later than males favoring the late allele (L), resulting in larger sizes and higher reproductive success. Males return to spawn at a younger age thus favoring the early (E) allele. The difference in the two reproductive strategies results in intralocus sexual conflict at the vgll3 locus where one sex favors the opposite allele favored by the other sex at a particular locus. Through a breeding behavior experiment, we aim to measure courtship and aggressive (agonistic) behaviors of breeding adult Atlantic salmon and measure reproductive fitness of adults related to vgll3 genotypes. This experiment will be carried out at the Norwegian Institute for Nature Research (NINA) research station, Ims Norway.
2 Distress
Fish used in the behavioral breeding experiment will be anesthetized prior to handling during weighing, measuring, and tagging procedures and allowed ample time for recovery to minimize distress. Fish will be removed from the breeding experiment if signs of distress are apparent and euthanized.
3 Expected benefit
This experiment will show how traits associated with different vgll3 genotypes influence reproductive decisions and influence the quality and quantity of offspring. This research is important because it will link phenotypic traits, vgll3 genotypes and reproductive fitness in order to understand how genetic variation and sexual conflict at this locus is maintained in Atlantic salmon. This research will aid fisheries management and conservation efforts by gaining insight into the reproductive decisions of this important commercial food and recreational angling fish.
4 Number of animals, and what kind
152 adult Atlantic salmon (Salmo salar) + 5000 swim-up fry . Adults used in the experiment are bred from wild-caught ‘living gene bank’ parents Atlantic salmon (hatching dates, 2015-2017) and released as pre-smolt parr into the Imsa River. Fish are recaptured (Sept-November) when returning to spawn at the Imsa River fish trap. These fish are usually have spent 1-2 years at sea (seawinters). Recaptured fish are held at the Ims station, separated by sex, and maintained for breeding purposes unrelated to this experiment by Ims staff. 96 adults (48 males, 48 females) will be used in the breeding experiment and will be euthanized and dissected afterward for gene expression studies. An additional 24 fish (12 males, 12 females) will be held at Ims to use as alternates in case fish need to be replaced in the experiment. 32 additional fish (16 males, 16 females) will have their gametes collected for fertilization experiments and released in the wild. All fish not used in the breeding experiment will be returned to the wild after the experiment is over. We estimate approximately 5000 offspring (swim-up fry stage, ~1 month after hatching) resulting from spawning which will be collected for genetics/parentage analysis the following spring.
Etterevaluering
Mattilsynet er forpliktet etter regelverket til å etterevaluere alle forsøk som er betydelig belastende for forsøksdyra og kan også be om etterevaluering av forsøk med lavere belastningsgrad.
Begrunnelse for etterevalueringen
Dette forsøket ble ikke gjennomført fordi det ikke kom inn tilstrekkelig antall gytefisk, noe som var vesentlig grunnlag for hele forsøket. Dette medførte at forsøket ikke kunne gjennomføres og ingen dyr ble brukt.
I søknaden ble dette også beskrevet et slikt scenario og at forsøket da ikke ville gjennomføres hvis tilstrekkelig antall gytefisk ikke var tilgjengelig.
I søknaden ble dette også beskrevet et slikt scenario og at forsøket da ikke ville gjennomføres hvis tilstrekkelig antall gytefisk ikke var tilgjengelig.