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Alternative reproductive tactics increase effective population size and decrease inbreeding in wild Atlantic salmon.

Perrier C, Normandeau É, Dionne M, Richard A, Bernatchez L - Evol Appl (2014)

Bottom Line: Moreover, mature male parr boosted the number of alleles found among progenies.Finally, mature male parr were in average less related to anadromous females than were anadromous males, likely because of asynchronous sexual maturation between mature male parr and anadromous fish of a given cohort.By increasing Nb and allelic richness, and by decreasing inbreeding, the reproductive contribution of mature male parr has important evolutionary and conservation implications for declining Atlantic salmon populations.

View Article: PubMed Central - PubMed

Affiliation: Département de Biologie, Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval Québec, Canada.

ABSTRACT
While nonanadromous males (stream-resident and/or mature male parr) contribute to reproduction in anadromous salmonids, little is known about their impacts on key population genetic parameters. Here, we evaluated the contribution of Atlantic salmon mature male parr to the effective number of breeders (Nb) using both demographic (variance in reproductive success) and genetic (linkage disequilibrium) methods, the number of alleles, and the relatedness among breeders. We used a recently published pedigree reconstruction of a wild anadromous Atlantic salmon population in which 2548 fry born in 2010 were assigned parentage to 144 anadromous female and 101 anadromous females that returned to the river to spawn in 2009 and to 462 mature male parr. Demographic and genetic methods revealed that mature male parr increased population Nb by 1.79 and 1.85 times, respectively. Moreover, mature male parr boosted the number of alleles found among progenies. Finally, mature male parr were in average less related to anadromous females than were anadromous males, likely because of asynchronous sexual maturation between mature male parr and anadromous fish of a given cohort. By increasing Nb and allelic richness, and by decreasing inbreeding, the reproductive contribution of mature male parr has important evolutionary and conservation implications for declining Atlantic salmon populations.

No MeSH data available.


Related in: MedlinePlus

Schematized life cycle of the Atlantic salmon population in the Escoumins River. This life cycle illustrates the potential generational links between the fry sampled in 2010 and the anadromous or mature male parr breeders from the most probable anterior cohorts.
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fig01: Schematized life cycle of the Atlantic salmon population in the Escoumins River. This life cycle illustrates the potential generational links between the fry sampled in 2010 and the anadromous or mature male parr breeders from the most probable anterior cohorts.

Mentions: Figure1 illustrates a typical life cycle of the Atlantic salmon population inhabiting the Escoumins River, showing the potential cohorts of anadromous and mature male parr breeders that may have contributed to the fry sampled in 2010. CERVUS and PASOS (Duchesne et al. 2005) were first used to find the most likely mother–offspring and father–offspring pairs. A total of 1247 paternities and 2395 maternities were identified. Then, the full likelihood approach implemented in COLONY (Jones and Wang 2010) was used to allocate a mother or a father to the 153 and 1301 remaining fry, respectively. Probability of identity and paternity exclusion probability combined across all loci was 5 × 10−6 for the first parent, allowing high-quality assignments (see Richard et al. 2013 for further details on assignment reliability). Although mature male parr were not sampled, COLONY was used to infer their genotypes from the pedigree analysis using a 0.60 probability that a father was present among the anadromous fish. To determine the effect of the number of offspring sampled on the potential for detection of anadromous parents and of mature male parr fathers, we subsampled from 50 to 2500 offspring by steps of 50, with each step being subsampled 1000 times. The number of parents identified should reach a plateau if enough offspring were sampled.


Alternative reproductive tactics increase effective population size and decrease inbreeding in wild Atlantic salmon.

Perrier C, Normandeau É, Dionne M, Richard A, Bernatchez L - Evol Appl (2014)

Schematized life cycle of the Atlantic salmon population in the Escoumins River. This life cycle illustrates the potential generational links between the fry sampled in 2010 and the anadromous or mature male parr breeders from the most probable anterior cohorts.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4231598&req=5

fig01: Schematized life cycle of the Atlantic salmon population in the Escoumins River. This life cycle illustrates the potential generational links between the fry sampled in 2010 and the anadromous or mature male parr breeders from the most probable anterior cohorts.
Mentions: Figure1 illustrates a typical life cycle of the Atlantic salmon population inhabiting the Escoumins River, showing the potential cohorts of anadromous and mature male parr breeders that may have contributed to the fry sampled in 2010. CERVUS and PASOS (Duchesne et al. 2005) were first used to find the most likely mother–offspring and father–offspring pairs. A total of 1247 paternities and 2395 maternities were identified. Then, the full likelihood approach implemented in COLONY (Jones and Wang 2010) was used to allocate a mother or a father to the 153 and 1301 remaining fry, respectively. Probability of identity and paternity exclusion probability combined across all loci was 5 × 10−6 for the first parent, allowing high-quality assignments (see Richard et al. 2013 for further details on assignment reliability). Although mature male parr were not sampled, COLONY was used to infer their genotypes from the pedigree analysis using a 0.60 probability that a father was present among the anadromous fish. To determine the effect of the number of offspring sampled on the potential for detection of anadromous parents and of mature male parr fathers, we subsampled from 50 to 2500 offspring by steps of 50, with each step being subsampled 1000 times. The number of parents identified should reach a plateau if enough offspring were sampled.

Bottom Line: Moreover, mature male parr boosted the number of alleles found among progenies.Finally, mature male parr were in average less related to anadromous females than were anadromous males, likely because of asynchronous sexual maturation between mature male parr and anadromous fish of a given cohort.By increasing Nb and allelic richness, and by decreasing inbreeding, the reproductive contribution of mature male parr has important evolutionary and conservation implications for declining Atlantic salmon populations.

View Article: PubMed Central - PubMed

Affiliation: Département de Biologie, Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval Québec, Canada.

ABSTRACT
While nonanadromous males (stream-resident and/or mature male parr) contribute to reproduction in anadromous salmonids, little is known about their impacts on key population genetic parameters. Here, we evaluated the contribution of Atlantic salmon mature male parr to the effective number of breeders (Nb) using both demographic (variance in reproductive success) and genetic (linkage disequilibrium) methods, the number of alleles, and the relatedness among breeders. We used a recently published pedigree reconstruction of a wild anadromous Atlantic salmon population in which 2548 fry born in 2010 were assigned parentage to 144 anadromous female and 101 anadromous females that returned to the river to spawn in 2009 and to 462 mature male parr. Demographic and genetic methods revealed that mature male parr increased population Nb by 1.79 and 1.85 times, respectively. Moreover, mature male parr boosted the number of alleles found among progenies. Finally, mature male parr were in average less related to anadromous females than were anadromous males, likely because of asynchronous sexual maturation between mature male parr and anadromous fish of a given cohort. By increasing Nb and allelic richness, and by decreasing inbreeding, the reproductive contribution of mature male parr has important evolutionary and conservation implications for declining Atlantic salmon populations.

No MeSH data available.


Related in: MedlinePlus