Effects of intraspecific hybridisation between two hatchery-reared strains of Atlantic salmon, Salmo salar, on juvenile survival and fitness-related traits

• Published in: Fisheries Management and Ecology
• Main Authors: Audet, Chantal L., Wilson, C. C., Pitcher, Trevor E.
• Format: Text
• Language: unknown
• Published: Scholarship at UWindsor 2017
• Subjects: Atlantic salmon; fitness; hybridization; juveniles; reintroduction; stocking; Biology; Life Sciences; Salmo salar
• Online Access: https://scholar.uwindsor.ca/biologypub/1198; https://doi.org/10.1111/fme.12195; https://scholar.uwindsor.ca/context/biologypub/article/2205/viewcontent/Audet_et_al.___2017___Effects_of_intraspecific_hybridisation_between_two.pdf

Intraspecific hybridisation may result in hybrid offspring exhibiting superior (heterosis) or inferior (outbreeding depression) fitness relative to their parental populations. As both have been demonstrated in salmonids, consequences of interbreeding between divergent populations are relevant to their conservation. Atlantic salmon Salmo salar L. were extirpated from Lake Ontario by the late 19th Century due to anthropogenic causes. Multiple allopatric populations of hatchery-reared Atlantic salmon are being stocked in an effort to re-establish a self-sustaining population. This study evaluated whether interbreeding between Sebago Lake (Maine) and LaHave River (Nova Scotia) individuals will result in heterosis or outbreeding depression in juveniles. This was accomplished through full-factorial 2 × 2 mating crosses between the strains and comparing multiple fitness-related traits between the cross types. Hybrid juveniles displayed no signs of outbreeding depression nor heterosis. Further studies on comparative fitness of backcross and F2 hybrids are recommended to assess potential consequences for this and similar restoration efforts.