title: Population genetics of the American eel (Anguilla rostrata): FST = 0 and North Atlantic Oscillation effects on demographic fluctuations of a panmictic species.
abstract: We performed population genetic analyses on the American eel (Anguilla rostrata) with three main objectives. First, we conducted the most comprehensive analysis of neutral genetic population structure to date to revisit the null hypothesis of panmixia in this species. Second, we used this data to provide the first estimates of contemporary effective population size (Ne ) and to document temporal variation in effective number of breeders (Nb ) in American eel. Third, we tested for statistical associations between temporal variation in the North Atlantic Oscillation (NAO), the effective number of breeders and two indices of recruit abundance. A total of 2142 eels from 32 sampling locations were genotyped with 18 microsatellite loci. All measures of differentiation were essentially zero, and no evidence for significant spatial or temporal genetic differentiation was found. The panmixia hypothesis should thus be accepted for this species. Nb estimates varied by a factor of 23 among 12 cohorts, from 473 to 10,999. The effective population size Ne was estimated at 10,532 (95% CI, 9312-11,752). This study also showed that genetically based demographic indices, namely Nb and allelic richness (Ar), can be used as surrogates for the abundance of breeders and recruits, which were both shown to be positively influenced by variation during high (positive) NAO phases. Thus, long-term genetic monitoring of American glass eels at several sites along the North American Atlantic coast would represent a powerful and efficient complement to census monitoring to track demographic fluctuations and better understand their causes.
authors.affiliation: Département de Biologie, IBIS (Institut de Biologie Intégrative et des Systèmes), Université Laval, Québec, Canada. caroline.cote.14@ulaval.ca
authors.forename: Caroline L
authors.initials: CL
authors.lastname: Côté
authors.forename: Pierre-Alexandre
authors.initials: PA
authors.lastname: Gagnaire
authors.forename: Vincent
authors.initials: V
authors.lastname: Bourret
authors.forename: Guy
authors.initials: G
authors.lastname: Verreault
authors.forename: Martin
authors.initials: M
authors.lastname: Castonguay
authors.forename: Louis
authors.initials: L
authors.lastname: Bernatchez
mesh_terms: D000483:Alleles; D000811:Anguilla / Q000145:classification* / Q000235:genetics*; D000818:Animals; D001267:Atlantic Ocean; D004247:DNA / Q000235:genetics; D005787:Gene Frequency; D056426:Genetic Loci; D014644:Genetic Variation; D005828:Genetics, Population; D005838:Genotype; D018895:Microsatellite Repeats; D009656:North America; D016133:Polymerase Chain Reaction; D011156:Population Density; D012098:Reproduction / Q000235:genetics
chemical_list: D004247:DNA