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Papers by Sana BEN KHADHER
HAL (Le Centre pour la Communication Scientifique Directe), 2019
In this study, the genetic diversity of Eurasian perch Perca fluviatilis was compared between two... more In this study, the genetic diversity of Eurasian perch Perca fluviatilis was compared between two lakes, Lake Geneva and Lake Neuchâtel, which are only separated by 50 km and often used to establish the broodstock for farming. Perch were sampled in six localities in Lake Geneva, and two localities in Lake Neuchâtel. Analyses were performed using twelve microsatellites in June 2012 (spawning period) and September 2012 (early autumn). Results revealed that perch populations in Lake Geneva were genetically different than those of Lake Neuchâtel. Genetic diversity of perch in Lake Neuchâtel (mean number of allele A = 6.91, allelic richness Ar = 5.19 and observed heterozygosity Ho = 0.607) were significantly higher than for perch in Lake Geneva (A = 6.08 Ar = 5.86 and Ho = 0.416). Some private alleles were present and characterize each lake population. According to FST-pairwise estimates, populations of the two lakes were significantly different. Some hypotheses that may explain this difference are discussed: the nature of the watershed and the anthropic pressures, as fishing pressure and aquaculture practices. Even at a fine-local scale, the choice of the origin of a wild population influences the initial genetic variability introduced in the farming system at the first step of domestication.
The diversification of production, by the domestication of ew fish species, is one of the possibl... more The diversification of production, by the domestication of ew fish species, is one of the possible solutions for sustainable aquaculture. In this context, the farming of the Eurasian perch, Perca fluviatilis, has developed well in recent years allowing today a stable and increasing production. The progress of the sector requires, among others, the establishment of breeding programs to improve, growth, reproduction and disease resistance. For this, the genetic characterization of currently farmed fish stocks is an essential prerequisite to assess whether genetic variation is sufficient. In this work, we analyzed the genetic variability among wild populations of two alpine lakes (lakes Geneva and Neuchâtel) whose populations are used by fish farmers to establish their stocks. We found one panmictic population in Lake Geneva, while two sub-populations were identified in Lake Neuchâtel, whose genetic variability is higher. However, those wild populations are not found in captive stocks. In addition, the genetic variability is higher in captive populations. Between parents and their offspring, the genetic diversity has not decreased despite a small increase in inbreeding. Thus, this work will allow fish farmers to set up a real genetic management of their stocks and subsequently to develop breeding programs. Moreover, it provides a better understanding of the possible links between the process of domestication and the evolution of genetic variability.
La diversification de la production, par la domestication de nouvelles espèces de poissons, const... more La diversification de la production, par la domestication de nouvelles espèces de poissons, constitue l’une des solutions pour une aquaculture durable. Dans ce contexte, l’élevage de la perche Eurasienne, Perca fluviatilis, s’est bien développé ces dernières années permettant aujourd’hui une production stable et croissante. Le progrès de la filière requiert, la mise en œuvre de programmes de sélection génétique pour améliorer, entre-autres, la croissance, la reproduction, et la résistance aux maladies. Pour ce faire, la caractérisation génétique des stocks de poisson actuellement en élevage est un pré-requis indispensable afin d’évaluer si la variabilité génétique est suffisante. Au cours de ce travail, nous avons analysé la variabilité génétique entre les populations sauvages de deux lacs alpins (lacs Léman et Neuchâtel) dont les populations sont utilisées comme fondatrices par les perciculteurs et les stocks de deux fermes d’élevage. Nous avons trouvé une seule population panmicti...
In this study, the genetic diversity of Eurasian perch Perca fluviatilis was compared between two... more In this study, the genetic diversity of Eurasian perch Perca fluviatilis was compared between two lakes, Lake Geneva and Lake Neuchâtel, which are only separated by 50 km and often used to establish the broodstock for farming. Perch were sampled in six localities in Lake Geneva, and two localities in Lake Neuchâtel. Analyses were performed using twelve microsatellites in June 2012 (spawning period) and September 2012 (early autumn). Results revealed that perch populations in Lake Geneva were genetically different than those of Lake Neuchâtel. Genetic diversity of perch in Lake Neuchâtel (mean number of allele A = 6.91, allelic richness Ar = 5.19 and observed heterozygosity Ho = 0.607) were significantly higher than for perch in Lake Geneva (A = 6.08 Ar = 5.86 and Ho = 0.416). Some private alleles were present and characterize each lake population. According to FST-pairwise estimates, populations of the two lakes were significantly different. Some hypotheses that may explain this dif...
La diversification de la production, par la domestication de nouvelles especes de poissons, const... more La diversification de la production, par la domestication de nouvelles especes de poissons, constitue l’une des solutions pour une aquaculture durable. Dans ce contexte, l’elevage de la perche Eurasienne, Perca fluviatilis, s’est bien developpe ces dernieres annees permettant aujourd’hui une production stable et croissante. Le progres de la filiere requiert, la mise en œuvre de programmes de selection genetique pour ameliorer, entre-autres, la croissance, la reproduction, et la resistance aux maladies. Pour ce faire, la caracterisation genetique des stocks de poisson actuellement en elevage est un pre-requis indispensable afin d’evaluer si la variabilite genetique est suffisante. Au cours de ce travail, nous avons analyse la variabilite genetique entre les populations sauvages de deux lacs alpins (lacs Leman et Neuchâtel) dont les populations sont utilisees comme fondatrices par les perciculteurs et les stocks de deux fermes d’elevage. Nous avons trouve une seule population panmicti...
Aquaculture Reports, 2016
Aquaculture of the Eurasian perch, Perca fluviatilis, in recirculating systems has emerged over t... more Aquaculture of the Eurasian perch, Perca fluviatilis, in recirculating systems has emerged over the past decades to become a significant way of diversification for inland areas in Europe. The development of such a production relies partly on the improvement of growth performance (i.e., reducing production costs), which requires suitable genetic management of broodstocks and the development of selective breeding programs. In this context, the present study was undertaken assessing for the first time the genetic diversity of farmed stocks of perch. Twelve microsatellite loci were used to investigate the genetic diversity of nine farmed stocks (547 individuals) from two perch farms located in France and their supposedly wild founder population from Lake Geneva (394 individuals). First, the wild population displayed the lowest genetic diversity and differed genetically from all farmed populations except one, XB2. Second, genetic diversity did not decrease between farmed breeders and their potential offspring. However, in the three groups of broodstock-offspring the number of alleles decreased by 10%, 21%, and 15%, respectively. In addition, effective population size decreased in all offspring groups. A family structuring was also observed among broodstocks and their offspring, with an unequal family contribution being suspected. In the absence of parental information, these results attest to the utility of genetic tools to evaluate genetic diversity and the necessity of a monitoring program to maintain genetic variability among farmed perch. Genetic variability among farmed stocks appears to be sufficient for perch production to be sustainable and selective breeding programs to be developed.
Journal of Great Lakes Research, 2015
The study provides the first analysis of the genetic structure of an economically and ecologicall... more The study provides the first analysis of the genetic structure of an economically and ecologically important fish species, Eurasian perch, in Lake Geneva. Twelve microsatellite markers were analyzed for 394 fish sampled at the end of the spawning season from seven sites located all around the lake (between 42 and 61 fish per site). The measure of genetic differentiation, F ST , was low overall (0.0035), but significant for twelve pairwise site comparisons. In contrast, Bayesian cluster analyses indicated no support for the presence of more than one distinct genetic cluster. We conclude that there is only one population in the lake. Therefore, the Eurasian perch should be managed as a single stock.
HAL (Le Centre pour la Communication Scientifique Directe), 2019
In this study, the genetic diversity of Eurasian perch Perca fluviatilis was compared between two... more In this study, the genetic diversity of Eurasian perch Perca fluviatilis was compared between two lakes, Lake Geneva and Lake Neuchâtel, which are only separated by 50 km and often used to establish the broodstock for farming. Perch were sampled in six localities in Lake Geneva, and two localities in Lake Neuchâtel. Analyses were performed using twelve microsatellites in June 2012 (spawning period) and September 2012 (early autumn). Results revealed that perch populations in Lake Geneva were genetically different than those of Lake Neuchâtel. Genetic diversity of perch in Lake Neuchâtel (mean number of allele A = 6.91, allelic richness Ar = 5.19 and observed heterozygosity Ho = 0.607) were significantly higher than for perch in Lake Geneva (A = 6.08 Ar = 5.86 and Ho = 0.416). Some private alleles were present and characterize each lake population. According to FST-pairwise estimates, populations of the two lakes were significantly different. Some hypotheses that may explain this difference are discussed: the nature of the watershed and the anthropic pressures, as fishing pressure and aquaculture practices. Even at a fine-local scale, the choice of the origin of a wild population influences the initial genetic variability introduced in the farming system at the first step of domestication.
The diversification of production, by the domestication of ew fish species, is one of the possibl... more The diversification of production, by the domestication of ew fish species, is one of the possible solutions for sustainable aquaculture. In this context, the farming of the Eurasian perch, Perca fluviatilis, has developed well in recent years allowing today a stable and increasing production. The progress of the sector requires, among others, the establishment of breeding programs to improve, growth, reproduction and disease resistance. For this, the genetic characterization of currently farmed fish stocks is an essential prerequisite to assess whether genetic variation is sufficient. In this work, we analyzed the genetic variability among wild populations of two alpine lakes (lakes Geneva and Neuchâtel) whose populations are used by fish farmers to establish their stocks. We found one panmictic population in Lake Geneva, while two sub-populations were identified in Lake Neuchâtel, whose genetic variability is higher. However, those wild populations are not found in captive stocks. In addition, the genetic variability is higher in captive populations. Between parents and their offspring, the genetic diversity has not decreased despite a small increase in inbreeding. Thus, this work will allow fish farmers to set up a real genetic management of their stocks and subsequently to develop breeding programs. Moreover, it provides a better understanding of the possible links between the process of domestication and the evolution of genetic variability.
La diversification de la production, par la domestication de nouvelles espèces de poissons, const... more La diversification de la production, par la domestication de nouvelles espèces de poissons, constitue l’une des solutions pour une aquaculture durable. Dans ce contexte, l’élevage de la perche Eurasienne, Perca fluviatilis, s’est bien développé ces dernières années permettant aujourd’hui une production stable et croissante. Le progrès de la filière requiert, la mise en œuvre de programmes de sélection génétique pour améliorer, entre-autres, la croissance, la reproduction, et la résistance aux maladies. Pour ce faire, la caractérisation génétique des stocks de poisson actuellement en élevage est un pré-requis indispensable afin d’évaluer si la variabilité génétique est suffisante. Au cours de ce travail, nous avons analysé la variabilité génétique entre les populations sauvages de deux lacs alpins (lacs Léman et Neuchâtel) dont les populations sont utilisées comme fondatrices par les perciculteurs et les stocks de deux fermes d’élevage. Nous avons trouvé une seule population panmicti...
In this study, the genetic diversity of Eurasian perch Perca fluviatilis was compared between two... more In this study, the genetic diversity of Eurasian perch Perca fluviatilis was compared between two lakes, Lake Geneva and Lake Neuchâtel, which are only separated by 50 km and often used to establish the broodstock for farming. Perch were sampled in six localities in Lake Geneva, and two localities in Lake Neuchâtel. Analyses were performed using twelve microsatellites in June 2012 (spawning period) and September 2012 (early autumn). Results revealed that perch populations in Lake Geneva were genetically different than those of Lake Neuchâtel. Genetic diversity of perch in Lake Neuchâtel (mean number of allele A = 6.91, allelic richness Ar = 5.19 and observed heterozygosity Ho = 0.607) were significantly higher than for perch in Lake Geneva (A = 6.08 Ar = 5.86 and Ho = 0.416). Some private alleles were present and characterize each lake population. According to FST-pairwise estimates, populations of the two lakes were significantly different. Some hypotheses that may explain this dif...
La diversification de la production, par la domestication de nouvelles especes de poissons, const... more La diversification de la production, par la domestication de nouvelles especes de poissons, constitue l’une des solutions pour une aquaculture durable. Dans ce contexte, l’elevage de la perche Eurasienne, Perca fluviatilis, s’est bien developpe ces dernieres annees permettant aujourd’hui une production stable et croissante. Le progres de la filiere requiert, la mise en œuvre de programmes de selection genetique pour ameliorer, entre-autres, la croissance, la reproduction, et la resistance aux maladies. Pour ce faire, la caracterisation genetique des stocks de poisson actuellement en elevage est un pre-requis indispensable afin d’evaluer si la variabilite genetique est suffisante. Au cours de ce travail, nous avons analyse la variabilite genetique entre les populations sauvages de deux lacs alpins (lacs Leman et Neuchâtel) dont les populations sont utilisees comme fondatrices par les perciculteurs et les stocks de deux fermes d’elevage. Nous avons trouve une seule population panmicti...
Aquaculture Reports, 2016
Aquaculture of the Eurasian perch, Perca fluviatilis, in recirculating systems has emerged over t... more Aquaculture of the Eurasian perch, Perca fluviatilis, in recirculating systems has emerged over the past decades to become a significant way of diversification for inland areas in Europe. The development of such a production relies partly on the improvement of growth performance (i.e., reducing production costs), which requires suitable genetic management of broodstocks and the development of selective breeding programs. In this context, the present study was undertaken assessing for the first time the genetic diversity of farmed stocks of perch. Twelve microsatellite loci were used to investigate the genetic diversity of nine farmed stocks (547 individuals) from two perch farms located in France and their supposedly wild founder population from Lake Geneva (394 individuals). First, the wild population displayed the lowest genetic diversity and differed genetically from all farmed populations except one, XB2. Second, genetic diversity did not decrease between farmed breeders and their potential offspring. However, in the three groups of broodstock-offspring the number of alleles decreased by 10%, 21%, and 15%, respectively. In addition, effective population size decreased in all offspring groups. A family structuring was also observed among broodstocks and their offspring, with an unequal family contribution being suspected. In the absence of parental information, these results attest to the utility of genetic tools to evaluate genetic diversity and the necessity of a monitoring program to maintain genetic variability among farmed perch. Genetic variability among farmed stocks appears to be sufficient for perch production to be sustainable and selective breeding programs to be developed.
Journal of Great Lakes Research, 2015
The study provides the first analysis of the genetic structure of an economically and ecologicall... more The study provides the first analysis of the genetic structure of an economically and ecologically important fish species, Eurasian perch, in Lake Geneva. Twelve microsatellite markers were analyzed for 394 fish sampled at the end of the spawning season from seven sites located all around the lake (between 42 and 61 fish per site). The measure of genetic differentiation, F ST , was low overall (0.0035), but significant for twelve pairwise site comparisons. In contrast, Bayesian cluster analyses indicated no support for the presence of more than one distinct genetic cluster. We conclude that there is only one population in the lake. Therefore, the Eurasian perch should be managed as a single stock.