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Patrick Williot - One of the best experts on this subject based on the ideXlab platform.
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Biology And Conservation Of The European Sturgeon Acipenser Sturio L, 1758. The Reunion of the European and Atlantic Sturgeons
2011Co-Authors: Patrick Williot, Eric Rochard, Jörn Gessner, Nathalie Desse-berset, Frank KirschbaumAbstract:Biology And Conservation Of The European Sturgeon Acipenser Sturio L, 1758. The Reunion of the European and Atlantic Sturgeons
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Historic Overview of the European Sturgeon Acipenser Sturio in France: Surveys, Regulations, Reasons for the Decline, Conservation, and Analysis: chap. 20
2011Co-Authors: Patrick Williot, Eric Rochard, Nathalie Desse-berset, Gérard Castelnaud, F. Kirschbaum, J GessnerAbstract:This chapter deals with an historical overview of sturgeon fishery in France and with preservation and conservation issues. It includes conclusions and recommendations of the many scientific surveys, which have almost always been neglected. The cause of the decline in the population, fishery regulations, and the deterioration of the environment are described in detail. Proposals for the preservation and conservation of the species from the late 1970s on are briefly presented. The subsequent three-leg strategy is described: (1) the necessity to improve our knowledge of the biology of the remaining population, (2) the inevitable restocking programme to sustain the population, and (3) the need to use another sturgeon species as a biological model to acquire experience on life-cycle characteristics and to develop methods of artificial reproduction for subsequent application to Acipenser Sturio. Conservation measures, both in situ and ex situ, are summarised. The analysis highlights the absence of (1) a resource-oriented fishery policy, and (2) measures to preserve biodiversity.
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some ex situ related approaches for assessing the biological variability of Acipenser Sturio
2011Co-Authors: Patrick WilliotAbstract:Intra-specific biological variability is the core subject of this chapter, the aim being to improve the effectiveness of the long-term restoration programme. This programme is divided into five steps (from brood-stock building to post-release monitoring), the first four being more exclusively part of the ex-situ actions. Each step comprises different key tasks. The following two sections of the chapter deal with the known biological variability of the brood stock, both genetic and behavioural. With regard to genetic variability, recent approaches based on genomics and proteomics are presented, with a brief analysis of the factors that may impact variability. Next, some proposals are made to meet short-term targets, i.e., those which can potentially be applied immediately, then medium- or long-term proposals which need additional research.
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recent progress in larval rearing of the european sturgeon Acipenser Sturio
2011Co-Authors: Patrick Chèvre, Daniel Mercier, Louis Jacobs, Julien Saintsevin, Patrick WilliotAbstract:This chapter deals with updated larvae management techniques, focusing on feed management. A compound diet was produced, and the reasoning behind this, the choice of ingredients, and manufacturing process are described here. Stocking, feeding sequences and results are also given. Co-feeding was based successively on 1-day-old Artemia salina nauplii (7–35 dph), chironomids (20–49 dph), and the compound diets (from 29 dph onwards). For 65-day-old fish raised at a water temperature range of 18.5–19°C, high survival rates (89%), and average weight of 3 g were recorded. Six-month-old fish weaned on compound diet weighed three times more (90 vs 35 g) than their naturally fed counterparts.
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preliminary results on larval rearing the european sturgeon Acipenser Sturio
2011Co-Authors: Patrick Williot, R Brun, T. Rouault, M. Pelard, D. MercierAbstract:This chapter reports on the first successful larval rearing of A. Sturio carried out in 1995. Four food items (two live prey and two compound diets) and water temperature were tested as first feeding, but with the constraint of saving as many fish as possible. As Artemia salina nauplii were first observed in the digestive tract, nauplii were added to all other batches. Nauplii alone provided the best growth until 23 days-post-hatch (dph). Water temperature of 21°C versus 17.5°C increased growth and mortality until 37 dph. Best survival post short weaning (3 days) at 17.5°C, depending on age at weaning initiation, was for 55 dph fish. For 50 dph fish, long weaning (3 weeks) provided better growth and survival than short weaning (3 days). Frozen chironomids proved to be impact-free on fish between 0.6 g and 2.9 g. Some conclusions are drawn for further improvements in larval rearing experiments.
Olivier Chassaing - One of the best experts on this subject based on the ideXlab platform.
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phylogeography of the european sturgeon Acipenser Sturio a critically endangered species
Molecular Phylogenetics and Evolution, 2016Co-Authors: Nathalie Desseberset, Olivier Chassaing, Sandrine Hughes, Catherine Hanni, Patrick BerrebiAbstract:The European sturgeon (Acipenser Sturio) was once a common species throughout Europe, but the sole remaining natural population presently inhabits the Gironde Estuary in France (Atlantic coast). The species was classified as 'Critically Endangered' in 1996, and the Gironde population is now on the verge of extinction. In this setting, and for the first time, we present the past phylogeographical features of this species throughout Europe along with an assessment of its former genetic diversity. This study was based on a molecular analysis (mtDNA CR sequencing) of 10 living specimens from the Gironde Estuary, 55 museum specimens that had been caught along 19th and 20th centuries, and 59 archaeological remains dating back to 260-5000years BP, from which mitochondrial DNA was extracted and amplified. Although discontinuous, the produced data provided a realistic image of the former structure of A. Sturio in Europe. Reconstruction of the phylogenetic trees and haplotypes network led to the identification of several clades. The mitochondrial genetic diversity of this species was found to be much greater at the core (Iberian Peninsula, Mediterranean and Adriatic regions) than along the margins (Atlantic-Northern Europe, Black Sea) of its range. A series of hypotheses on the dates and causes of changes in the species' major structures are put forward on the basis of these data. Finally, competition with A. oxyrinchus, a sibling species whose presence in Northern Europe was recently reconsidered, is presented as a major factor in the evolution of this species.
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palaeogenetics of western french sturgeons spotlights the relationships between Acipenser Sturio and Acipenser oxyrinchus
Journal of Biogeography, 2013Co-Authors: Nathalie Desseberset, Olivier Chassaing, Marilyne Duffraisse, Sandrine Hughes, Catherine Hanni, Patrick BerrebiAbstract:Aim The Atlantic sturgeon, Acipenser oxyrinchus, was long considered an American species, but recent discoveries based on analyses of archaeological remains proved its presence in the Baltic Sea and in France. This came as a surprise, as the European sturgeon, Acipenser Sturio, was thought to be the only sturgeon species present on the European Atlantic coast. It was hypothesized that migrants from North America founded the Baltic population of Atlantic sturgeons around 1200 years ago. Location The sampling is composed of five sturgeon archaeological remains (5000–1800 yr bp) and 21 naturalized or ethanol-preserved museum specimens from the 19th and 20th centuries, originating from the French Atlantic coast. Methods Analyses of ancient DNA were performed following the strict criteria of the field to avoid contamination and to ensure sequence authentication. A 210-bp fragment of the control region (CR) was sequenced and three microsatellite loci were sized and sequenced. Results Out of a total of 26 samples, three archaeological remains and six museum specimens produced A. oxyrinchus mitochondrial or nuclear sequences; two of these museum samples showed signs of hybridization between A. Sturio and A. oxyrinchus. All the other samples yielded only A. Sturio DNA sequences, and a new CR haplotype was described in this species. Main conclusions Molecular evidence of sympatry and natural hybridization between A. Sturio and A. oxyrinchus on the French Atlantic coast – specifically the hybrid evidence of two museum specimens collected from the Seine River in 1823 and 1858 – challenge our understanding of the species' past relationships. In light of these findings, new hypotheses are presented to explain the history and geographical range of A. oxyrinchus in Europe.
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sturgeons spotlights the relationships between Acipenser Sturio and Acipenser
2013Co-Authors: Olivier Chassaing, Nathalie Desseberset, Marilyne Duffraisse, Sandrine Hughes, Patrick BerrebiAbstract:Aim The Atlantic sturgeon, Acipenser oxyrinchus, was long considered an American species, but recent discoveries based on analyses of archaeological remains proved its presence in the Baltic Sea and in France. This came as a surprise, as the European sturgeon, Acipenser Sturio, was thought to be the only sturgeon species present on the European Atlantic coast. It was hypothesized that migrants from North America founded the Baltic population of Atlantic sturgeons around 1200 years ago. Location The sampling is composed of five sturgeon archaeological remains (5000–1800 yr bp) and 21 naturalized or ethanol-preserved museum specimens from the 19th and 20th centuries, originating from the French Atlantic coast. Methods Analyses of ancient DNA were performed following the strict criteria of the field to avoid contamination and to ensure sequence authentication. A 210-bp fragment of the control region (CR) was sequenced and three microsatellite loci were sized and sequenced. Results Out of a total of 26 samples, three archaeological remains and six museum specimens produced A. oxyrinchus mitochondrial or nuclear sequences; two of these museum samples showed signs of hybridization between A. Sturio and A. oxyrinchus. All the other samples yielded only A. Sturio DNA sequences, and a new CR haplotype was described in this species. Main conclusions Molecular evidence of sympatry and natural hybridization between A. Sturio and A. oxyrinchus on the French Atlantic coast – specifically the hybrid evidence of two museum specimens collected from the Seine River in 1823 and 1858 – challenge our understanding of the species’ past relationships. In light of these findings, new hypotheses are presented to explain the history and geographical range of A. oxyrinchus in Europe.
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organisation genetique des populations d esturgeon europeen Acipenser Sturio passe present futur
2010Co-Authors: Olivier ChassaingAbstract:L'esturgeon europeen Acipenser Sturio (Linnaeus, 1758) etait un poisson commun de nos fleuves jusqu'au debut du 20e siecle. Toutes ses populations sont maintenant eteintes sauf une qui survit dans le bassin Gironde-Garonne-Dordogne en France. Les donnees disponibles sur l'espece restent tres partielles car elles proviennent quasi exclusivement de cette population relictuelle. Au cours de cette these, plus d'une centaine d'echantillons anciens d'esturgeons restes archeologiques ou specimens naturalises conserves dans les museums d'histoire naturelle ont ete analyse grâce aux methodes de la paleogenetique. Ces analyses genetiques ont ete realisees sur l'ADN mitochondrial (surtout la Dloop) ainsi que sur cinq loci microsatellites qu'il a ete necessaire d'adapter aux methodes d'etude de l'ADN ancien. Les donnees paleogenetiques obtenues ont permis d'etudier : 1) les relations de l'esturgeon europeen avec les autres especes d'esturgeons vivant ou ayant vecu en Europe, en particulier l'esturgeon de l'Adriatique A. naccarii et l'esturgeon atlantique A. oxyrinchus. 2) la diversite genetique de l'esturgeon europeen sur l'ensemble de son ancienne aire de repartition. 3) la diversite genetique d'une population d'esturgeon europeen au cours du temps la population du Rhone, d'une periode ou elle etait florissante jusqu'a son extinction. L'ensemble de ces donnees ont ete discute a la lumiere de la conservation de l'espece, qui est aujourd'hui en danger critique d'extinction.
Patrick Berrebi - One of the best experts on this subject based on the ideXlab platform.
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phylogeography of the european sturgeon Acipenser Sturio a critically endangered species
Molecular Phylogenetics and Evolution, 2016Co-Authors: Nathalie Desseberset, Olivier Chassaing, Sandrine Hughes, Catherine Hanni, Patrick BerrebiAbstract:The European sturgeon (Acipenser Sturio) was once a common species throughout Europe, but the sole remaining natural population presently inhabits the Gironde Estuary in France (Atlantic coast). The species was classified as 'Critically Endangered' in 1996, and the Gironde population is now on the verge of extinction. In this setting, and for the first time, we present the past phylogeographical features of this species throughout Europe along with an assessment of its former genetic diversity. This study was based on a molecular analysis (mtDNA CR sequencing) of 10 living specimens from the Gironde Estuary, 55 museum specimens that had been caught along 19th and 20th centuries, and 59 archaeological remains dating back to 260-5000years BP, from which mitochondrial DNA was extracted and amplified. Although discontinuous, the produced data provided a realistic image of the former structure of A. Sturio in Europe. Reconstruction of the phylogenetic trees and haplotypes network led to the identification of several clades. The mitochondrial genetic diversity of this species was found to be much greater at the core (Iberian Peninsula, Mediterranean and Adriatic regions) than along the margins (Atlantic-Northern Europe, Black Sea) of its range. A series of hypotheses on the dates and causes of changes in the species' major structures are put forward on the basis of these data. Finally, competition with A. oxyrinchus, a sibling species whose presence in Northern Europe was recently reconsidered, is presented as a major factor in the evolution of this species.
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Parentage assignment in the critically endangered European sturgeon (Acipenser Sturio) based on a novel microsatellite multiplex assay: a valuable resource for restocking, monitoring and conservation programs
Conservation Genetics Resources, 2016Co-Authors: S. Roques, Eric Rochard, Patrick Berrebi, Patrick Chèvre, Marie-laure AcolasAbstract:The only remaining population of the critically endangered European sturgeon, Acipenser Sturio, is located in the Gironde basin (France). A restoration program initiated 20 years ago has allowed more than one and a half million individuals to be stocked. Effective monitoring of this population is a key prerequisite in ensuring the sustainability of this species in the wild. We report the development of a novel microsatellite multiplex assay for genetic monitoring of A. Sturio. Diversity of a set of 18 loci was low to moderate, with a number of alleles and observed heterozygosity ranging from 4 to 7 and 0.33 to 0.74 respectively, depending on markers. A set of captive-born progeny of known relatives (n = 72) was used to examine the efficiency of this assay in assigning parentage to offspring. Three different programs were used. Correct assignment success was generally high (above 90 %), but differed between programs. Parentage analysis of individuals captured in the Gironde estuary (n = 193) demonstrated that most offspring (91.2 %) are unambiguously allocated to parent pairs from the broodstock. Our research provides an efficient and accurate method for the genetic monitoring of the restocking program, but also for others aspects of conservation, including genetic diversity evaluation, effective population size estimation, and inbreeding assessment.
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palaeogenetics of western french sturgeons spotlights the relationships between Acipenser Sturio and Acipenser oxyrinchus
Journal of Biogeography, 2013Co-Authors: Nathalie Desseberset, Olivier Chassaing, Marilyne Duffraisse, Sandrine Hughes, Catherine Hanni, Patrick BerrebiAbstract:Aim The Atlantic sturgeon, Acipenser oxyrinchus, was long considered an American species, but recent discoveries based on analyses of archaeological remains proved its presence in the Baltic Sea and in France. This came as a surprise, as the European sturgeon, Acipenser Sturio, was thought to be the only sturgeon species present on the European Atlantic coast. It was hypothesized that migrants from North America founded the Baltic population of Atlantic sturgeons around 1200 years ago. Location The sampling is composed of five sturgeon archaeological remains (5000–1800 yr bp) and 21 naturalized or ethanol-preserved museum specimens from the 19th and 20th centuries, originating from the French Atlantic coast. Methods Analyses of ancient DNA were performed following the strict criteria of the field to avoid contamination and to ensure sequence authentication. A 210-bp fragment of the control region (CR) was sequenced and three microsatellite loci were sized and sequenced. Results Out of a total of 26 samples, three archaeological remains and six museum specimens produced A. oxyrinchus mitochondrial or nuclear sequences; two of these museum samples showed signs of hybridization between A. Sturio and A. oxyrinchus. All the other samples yielded only A. Sturio DNA sequences, and a new CR haplotype was described in this species. Main conclusions Molecular evidence of sympatry and natural hybridization between A. Sturio and A. oxyrinchus on the French Atlantic coast – specifically the hybrid evidence of two museum specimens collected from the Seine River in 1823 and 1858 – challenge our understanding of the species' past relationships. In light of these findings, new hypotheses are presented to explain the history and geographical range of A. oxyrinchus in Europe.
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sturgeons spotlights the relationships between Acipenser Sturio and Acipenser
2013Co-Authors: Olivier Chassaing, Nathalie Desseberset, Marilyne Duffraisse, Sandrine Hughes, Patrick BerrebiAbstract:Aim The Atlantic sturgeon, Acipenser oxyrinchus, was long considered an American species, but recent discoveries based on analyses of archaeological remains proved its presence in the Baltic Sea and in France. This came as a surprise, as the European sturgeon, Acipenser Sturio, was thought to be the only sturgeon species present on the European Atlantic coast. It was hypothesized that migrants from North America founded the Baltic population of Atlantic sturgeons around 1200 years ago. Location The sampling is composed of five sturgeon archaeological remains (5000–1800 yr bp) and 21 naturalized or ethanol-preserved museum specimens from the 19th and 20th centuries, originating from the French Atlantic coast. Methods Analyses of ancient DNA were performed following the strict criteria of the field to avoid contamination and to ensure sequence authentication. A 210-bp fragment of the control region (CR) was sequenced and three microsatellite loci were sized and sequenced. Results Out of a total of 26 samples, three archaeological remains and six museum specimens produced A. oxyrinchus mitochondrial or nuclear sequences; two of these museum samples showed signs of hybridization between A. Sturio and A. oxyrinchus. All the other samples yielded only A. Sturio DNA sequences, and a new CR haplotype was described in this species. Main conclusions Molecular evidence of sympatry and natural hybridization between A. Sturio and A. oxyrinchus on the French Atlantic coast – specifically the hybrid evidence of two museum specimens collected from the Seine River in 1823 and 1858 – challenge our understanding of the species’ past relationships. In light of these findings, new hypotheses are presented to explain the history and geographical range of A. oxyrinchus in Europe.
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Historical presence of the sturgeon Acipenser Sturio in the Rhône basin determined by the analysis of ancient DNA cytochrome b sequences
Conservation Genetics, 2009Co-Authors: Marie Pagès, Laurent Brosse, Nathalie Desse-berset, Catherine Hanni, Christelle Tougard, Patrick BerrebiAbstract:Sturgeon disappeared from the Rhône River in the mid 70's without certitude about which species it was and about the existence of a sympatry between European sturgeon, Acipenser Sturio, and Adriatic sturgeon, A. naccarii, in this watershed. In order to reach a reliable specific determination of this extinct sturgeon population, archaeozoological remains of the Jardin d'Hiver in Arles city, on the Rhône river banks, were genetically analysed, following strict criteria of authentication for the ancient DNA work. The rich collection of Arles sturgeon bone remains stems from human activities between the 6th and the 2nd Century BC. Sequences of 86 bp of the cytochrome b gene were obtained on four bones, from different anatomical parts of the fish and from different archaeological layers. All gave A. Sturio diagnostic sequences. This preliminary analysis is an essential first step in the project of sturgeon reintroduction in the Rhône River. Thus, further analyses on a larger sample are necessary to comfort this result and to solve the question of sympatry with A. naccarii.
Frank Kirschbaum - One of the best experts on this subject based on the ideXlab platform.
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Biology And Conservation Of The European Sturgeon Acipenser Sturio L, 1758. The Reunion of the European and Atlantic Sturgeons
2011Co-Authors: Patrick Williot, Eric Rochard, Jörn Gessner, Nathalie Desse-berset, Frank KirschbaumAbstract:Biology And Conservation Of The European Sturgeon Acipenser Sturio L, 1758. The Reunion of the European and Atlantic Sturgeons
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ontogeny of the european sturgeon Acipenser Sturio
2011Co-Authors: Frank Kirschbaum, Patrick WilliotAbstract:Early development from late embryo stage [stage 34 (stage numbers correspond to the description of Dettlaff et al. (1993) Sturgeon fishes. Developmental biology and aquaculture. Springer, Berlin)] up to exogenous feeding (stage 44) is described in the European sturgeon, Acipenser Sturio. The habit is documented in dorsal and lateral views from the larval stage up to adulthood. Special emphasis is given to the morphological development of the dorsal bony scutes and their dorsal spikes. First dorsal scutes occur in 21-day-old larvae, 20 mm long. In juveniles 15 cm long, the dorsal scutes and their dorsal, caudally oriented spikes are very prominent. In older juveniles the spikes regress; in 30 cm long juveniles the spikes have nearly disappeared. The ontogeny of the incomplete cover of the gills by the operculum is shown. The distribution of the ampullary electroreceptors in a 27-day-old larva is described.
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genetic variability of cultured european sturgeon Acipenser Sturio
2011Co-Authors: Ralph Tiedemann, Patrick Williot, Anja R R Schneider, Frank KirschbaumAbstract:From the relict population of the European sturgeon Acipenser Sturio, a captive breeding stock of specimens has been established in France, in order to prevent extinction of this species and to produce offspring to be released again to the wild. We genetically analyzed 23 wild-caught specimens of this French captive population, as well as 27 specimens of artificially produced offspring, at 12 newly developed microsatellite loci. We quantify the genetic distance among any pair of sturgeons belonging to the captive stock. In order to maintain the genetic variability and minimize inbreeding, we suggest dissortative mating, i.e., mating of any reproducing female with a distantly related male. We explicitly identify such genetically distant suitable mates for any female of the French breeding stock. Forced dissortative mating could be facilitated by cryoconservation of sperm, such that sperm of putatively suitable partners would be available at any time.
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restoration of the european sturgeon Acipenser Sturio in germany
2011Co-Authors: Frank Kirschbaum, Ralph Tiedemann, Patrick Williot, Frank Fredrich, Jörn GessnerAbstract:The onset of practical restoration measures on Acipenser Sturio in Germany is represented by the transfer of 40 one-year-old juveniles from the French Cemagref to the German Leibniz-Institute of Freshwater Ecology and Inland Fisheries in 1996 as a result of a bilateral cooperation. Molecular genetic studies revealed that these fish from the Garonne river system represented suitable material for the re-introduction into the tributaries of the North Sea. The fish were used for behavioural, feeding, and rearing experiments to improve the husbandry practice in fresh water. In 2005, a first female developed ripe gonad for the first time but artificial reproduction had not been accomplished to date. Subsequent transfers of juveniles in 2007, 2009, and 2010 allowed the expansion of the German brood stock, as well as first experimental releases both with tagged and telemetry transmitters to verify habitat utilization, migration patterns, and – through catch data – growth of the fish in the rivers Elbe, Oste, and Stor.
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the french german cooperation the key issue for the success of the preservation and restoration of the european sturgeon Acipenser Sturio and its significance for other sturgeon issues
2011Co-Authors: Patrick Williot, Frank KirschbaumAbstract:The first elements of the French–German cooperation arose in 1993 at a sturgeon meeting in Moscow, and the actual initiation represented the transfer of 40 juvenile Acipenser Sturio from France to Germany in 1996. This resulted in an extensive exchange of ideas, material, and data concerning the biology and restoration of A. Sturio between the two institutions Cemagref and Leibniz-Institute of Freshwater Ecology and Inland Fisheries, and in addition stimulated many studies on sturgeon biology in general. This will be outlined in this chapter, describing in short the main results and adding the appropriate references. We believe that the French–German cooperation was the key point for the success of the restoration efforts both in France and Germany.
Nathalie Desseberset - One of the best experts on this subject based on the ideXlab platform.
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phylogeography of the european sturgeon Acipenser Sturio a critically endangered species
Molecular Phylogenetics and Evolution, 2016Co-Authors: Nathalie Desseberset, Olivier Chassaing, Sandrine Hughes, Catherine Hanni, Patrick BerrebiAbstract:The European sturgeon (Acipenser Sturio) was once a common species throughout Europe, but the sole remaining natural population presently inhabits the Gironde Estuary in France (Atlantic coast). The species was classified as 'Critically Endangered' in 1996, and the Gironde population is now on the verge of extinction. In this setting, and for the first time, we present the past phylogeographical features of this species throughout Europe along with an assessment of its former genetic diversity. This study was based on a molecular analysis (mtDNA CR sequencing) of 10 living specimens from the Gironde Estuary, 55 museum specimens that had been caught along 19th and 20th centuries, and 59 archaeological remains dating back to 260-5000years BP, from which mitochondrial DNA was extracted and amplified. Although discontinuous, the produced data provided a realistic image of the former structure of A. Sturio in Europe. Reconstruction of the phylogenetic trees and haplotypes network led to the identification of several clades. The mitochondrial genetic diversity of this species was found to be much greater at the core (Iberian Peninsula, Mediterranean and Adriatic regions) than along the margins (Atlantic-Northern Europe, Black Sea) of its range. A series of hypotheses on the dates and causes of changes in the species' major structures are put forward on the basis of these data. Finally, competition with A. oxyrinchus, a sibling species whose presence in Northern Europe was recently reconsidered, is presented as a major factor in the evolution of this species.
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palaeogenetics of western french sturgeons spotlights the relationships between Acipenser Sturio and Acipenser oxyrinchus
Journal of Biogeography, 2013Co-Authors: Nathalie Desseberset, Olivier Chassaing, Marilyne Duffraisse, Sandrine Hughes, Catherine Hanni, Patrick BerrebiAbstract:Aim The Atlantic sturgeon, Acipenser oxyrinchus, was long considered an American species, but recent discoveries based on analyses of archaeological remains proved its presence in the Baltic Sea and in France. This came as a surprise, as the European sturgeon, Acipenser Sturio, was thought to be the only sturgeon species present on the European Atlantic coast. It was hypothesized that migrants from North America founded the Baltic population of Atlantic sturgeons around 1200 years ago. Location The sampling is composed of five sturgeon archaeological remains (5000–1800 yr bp) and 21 naturalized or ethanol-preserved museum specimens from the 19th and 20th centuries, originating from the French Atlantic coast. Methods Analyses of ancient DNA were performed following the strict criteria of the field to avoid contamination and to ensure sequence authentication. A 210-bp fragment of the control region (CR) was sequenced and three microsatellite loci were sized and sequenced. Results Out of a total of 26 samples, three archaeological remains and six museum specimens produced A. oxyrinchus mitochondrial or nuclear sequences; two of these museum samples showed signs of hybridization between A. Sturio and A. oxyrinchus. All the other samples yielded only A. Sturio DNA sequences, and a new CR haplotype was described in this species. Main conclusions Molecular evidence of sympatry and natural hybridization between A. Sturio and A. oxyrinchus on the French Atlantic coast – specifically the hybrid evidence of two museum specimens collected from the Seine River in 1823 and 1858 – challenge our understanding of the species' past relationships. In light of these findings, new hypotheses are presented to explain the history and geographical range of A. oxyrinchus in Europe.
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sturgeons spotlights the relationships between Acipenser Sturio and Acipenser
2013Co-Authors: Olivier Chassaing, Nathalie Desseberset, Marilyne Duffraisse, Sandrine Hughes, Patrick BerrebiAbstract:Aim The Atlantic sturgeon, Acipenser oxyrinchus, was long considered an American species, but recent discoveries based on analyses of archaeological remains proved its presence in the Baltic Sea and in France. This came as a surprise, as the European sturgeon, Acipenser Sturio, was thought to be the only sturgeon species present on the European Atlantic coast. It was hypothesized that migrants from North America founded the Baltic population of Atlantic sturgeons around 1200 years ago. Location The sampling is composed of five sturgeon archaeological remains (5000–1800 yr bp) and 21 naturalized or ethanol-preserved museum specimens from the 19th and 20th centuries, originating from the French Atlantic coast. Methods Analyses of ancient DNA were performed following the strict criteria of the field to avoid contamination and to ensure sequence authentication. A 210-bp fragment of the control region (CR) was sequenced and three microsatellite loci were sized and sequenced. Results Out of a total of 26 samples, three archaeological remains and six museum specimens produced A. oxyrinchus mitochondrial or nuclear sequences; two of these museum samples showed signs of hybridization between A. Sturio and A. oxyrinchus. All the other samples yielded only A. Sturio DNA sequences, and a new CR haplotype was described in this species. Main conclusions Molecular evidence of sympatry and natural hybridization between A. Sturio and A. oxyrinchus on the French Atlantic coast – specifically the hybrid evidence of two museum specimens collected from the Seine River in 1823 and 1858 – challenge our understanding of the species’ past relationships. In light of these findings, new hypotheses are presented to explain the history and geographical range of A. oxyrinchus in Europe.
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discrimination of Acipenser Sturio Acipenser oxyrinchus and Acipenser naccarii by morphology of bones and osteometry
2011Co-Authors: Nathalie DessebersetAbstract:Studying ancient sturgeon populations according to archaeological remains requires the identification of the species through bone morphology. Osteometry makes it possible to determine the different sizes and age categories of ancient specimens by measuring specific bones which are correlated with the same measurements taken on modern specimens of known total length (TL) and mass. These references have been established for Acipenser Sturio, Acipenser oxyrinchus (both attested in Europe from the Neolithic) and Acipenser naccarii, providing a set of morphological and osteometric criteria to discriminate the above-mentioned species. Through these methods, the size distribution of ancient sturgeons of different periods and locations can be reconstructed. The frequent presence of large-sized specimens of A. Sturio and A. oxyrinchus on the French Atlantic and North basins strongly suggests their sympatry.
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brief introduction to sturgeon with a special focus on the european sturgeon Acipenser Sturio l 1758
2011Co-Authors: Patrick Williot, Eric Rochard, Jörn Gessner, Nathalie Desseberset, Frank KirschbaumAbstract:Sturgeon comprise a small family of fish with 4 genera and 27 species. The genus Acipenser accounts for 17 species. In general, they are known for their large size, their unusual appearance, and their famous fish product, caviar. They are ancient fish ranging only over the northern hemisphere. All Eurasian sturgeon species are currently under threat, while the situation is slightly better in America. The European sturgeon colonized the continent from the Black Sea to the Baltic, through the Mediterranean, the Western Atlantic Ocean, the English Channel, and the North Sea (Fig. 1.1).
