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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, 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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Atlantic sturgeons (Acipenser sturio, Acipenser oxyrinchus): American females successful in Europe
Naturwissenschaften, 2007Co-Authors: Ralph Tiedemann, Katja Moll, Kirsten B. Paulus, Michael Scheer, Ryszard Bartel, Jörn Gessner, Frank KirschbaumAbstract:Recent molecular data on the maternally inherited mitochondrial (mt) DNA have challenged the traditional view that the now extinct Baltic sturgeon population belonged to the European sturgeon Acipenser sturio . Instead, there is evidence that American sea sturgeon Acipenser oxyrinchus historically immigrated into the Baltic Sea. In this study, we test the hypothesis that A. oxyrinchus introgressed into, rather than replaced, the A. sturio population in the Baltic. We established four single nucleotide polymorphisms (SNPs) in the nuclear MHC II antigen gene with a species-specific SNP pattern. Using an ancient DNA approach and two independent lines of molecular evidence (sequencing of allele-specific clones, SNaPshot), we detected both A. sturio and A. oxyrinchus alleles in the available museum material of the now extinct Baltic sturgeon population. The hybrid nature of the Baltic population was further confirmed by very high levels of heterozygosity. It had been previously postulated that the immigration of the cold-adapted A. oxyrinchus into the Baltic occurred during the Medieval Little Ice Age, when temperature likely dropped below the degree inducing spawning in A. sturio . Under this scenario, our new findings suggest that the genetic mosaic pattern in the Baltic sturgeon population ( oxyrinchus mtDNA, sturio and oxyrinchus MHC alleles) is possibly caused by sex-biased introgression where spawning was largely restricted to immigrating American females, while fertilization was predominantly achieved by abundant local European males. The hybrid nature of the former Baltic sturgeon population should be taken into account in the current reintroduction measures.
Arne Ludwig - One of the best experts on this subject based on the ideXlab platform.
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first evidence of hybridization between endangered sterlets Acipenser ruthenus and exotic siberian sturgeons Acipenser baerii in the danube river
Biological Invasions, 2009Co-Authors: Arne Ludwig, Sebastian Lippold, Lutz Debus, Ralf ReinartzAbstract:Most natural populations of Eurasian sturgeons have declined dramatically during recent decades, reaching historic low levels today. During the same period, sturgeon has become very popular in European aquaculture. Because many hatcheries are located near rivers, their unintentional escape is often documented, especially during floods. Until now, no cases of successful hybridization of these escaped fish with wild stocks have been reported. In this study, the genetic structure of a highly threatened population of sterlets (Acipenser ruthenus) from the Upper Danube was analysed as a requirement for their conservation. Surprisingly, we observed genotypes and morphotypes of Siberian sturgeon (Acipenser baerii), as well as hybrids between this species and native sterlets. This hybridization poses a serious threat for the survival of this isolated sterlet population in the upper part of the Danube. For the first time, natural reproduction is documented for Siberian sturgeon outside their natural range in Europe. This finding demonstrates the risk of extinction by hybridisation of endangered populations. We would like to stress that taking into consideration the risks for native sturgeon populations, farmed sturgeon should not be released into the wild, and all measures should be taken to prevent their accidental escape.
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the molecular phylogeny of the order Acipenseriformes revisited
Journal of Applied Ichthyology, 2008Co-Authors: Jeannette Krieger, Paul A Fuerst, Anne Kathrin Hett, E Artyukhin, Arne LudwigAbstract:Summary As evolutionary relationships within the order Acipenseriformes are not well understood and some classifications are currently controversial, the study of evolutionary relationships, especially based on genetic data, has received much recent attention. In this reanalysis we present a nearly complete proposed phylogeny of the order, including 25 species, based on the maximum likelihood analysis of combined DNA sequence data (4406 base pairs) from five mitochondrial genes sequenced in our laboratories (cytochrome b, 12S rRNA, cytochrome c oxidase subunit II, tRNAAsp and tRNAPhe) and three mitochondrial gene regions sequenced by Birstein et al. (2002) (16S rRNA, NADH5 and control region). Examination of the molecular phylogeny using either maximum likelihood, Bayesian analysis, maximum parsimony or neighbor-joining leads to the following conclusions: (i) the two species of paddlefish do form a clade; (ii) the most basal position within the Acipenseridae remains unresolved, held either by the genus Scaphirhynchus or by the clade containing Acipenser oxyrinchus and A. sturio; (iii) Huso is not monophyletic, with the two species of Huso found embedded separately within the genus Acipenser; (iv) A. sinensis and A. dabryanus are confirmed as closely related; (v) the previously described Atlantic-Pacific subdivision within the Acipenser ⁄ Huso complex is supported and (vi) the unexpected placement of Pseudoscaphirhynchus kaufmanni within Acipenser is supported by this analysis. These results offer further evidence that some revision of Acipenseriform classification may be needed to accurately inform conservation efforts and that future phylogenetic studies of this group should focus on the analysis of nuclear genes.
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evidence of mitochondrial dna clones of siberian sturgeon Acipenser baerii within russian sturgeon Acipenser gueldenstaedtii caught in the river volga
Ecology Letters, 2000Co-Authors: Ingo Jenneckens, Lutz Debus, J N Meyer, C Pitra, Arne LudwigAbstract:Eleven of 34 sturgeons caught in the River Volga classified morphologically as Acipenser gueldenstaedtii were identified as Acipenser baerii from sequence analysis of the mitochondrial cytochrome-b gene. The Caspian Sea and its tributaries including the Volga are not native habitats of A. baerii. No A. baerii haplotype was observed in A. gueldenstaedtii from the Sea of Azov or the South Caspian Sea. Genetic contamination of A. gueldenstaedtii with A. baerii or A. baerii hybrids has occurred in the Volga. Crosses and backcrosses of these specimens with native A. gueldenstaedtii resulted in the loss of the morphological diagnostic A. baerii features. These findings are of special concern for conservation and management programmes, as well as for specimen identification for caviar trading control.
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, 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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l elevage de l esturgeon siberien Acipenser baerii brandt en france
Cahiers Agricultures, 2009Co-Authors: Patrick WilliotAbstract:L’objectif de cet article est de fournir une synthese des conditions dans lesquelles l’elevage de l’esturgeon siberien (Acipenser baerii Brandt) a ete realise en France. Cette espece a ete utilisee comme modele biologique pour la sauvegarde de l’espece indigene en danger : l’esturgeon atlantique europeen, Acipenser sturio. Successivement sont decrits : les origines de cette activite, les diverses phases de son developpement, jusqu’a la situation actuelle, et quelques reflexions en guise de perspective. Un accent particulier est mis sur les actions de recherche.
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Hormonal profile in adult European sturgeon, Acipenser sturio, adapted to hatchery conditions in France
Cybium : Revue Internationale d’Ichtyologie, 2008Co-Authors: B. Davail Cuisset, Mario Lepage, Paul Gonthier, Patrick Williot, S. Lacomme, E. Viaene, S. Davail, T. RouaultAbstract:Plasma levels of estradiol (E2) testosterone (T), 11-etotestosterone, 17,20bP and vitellogenin (VTG ) are reported for the first time in mature male and female sturgeon, Acipenser sturio. T (40 ng/ml) correlates each year with spermiation. High E2 (33 ng/ml) correlates with VTG (90 mg/ml) and maturation.
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sturgeon farming in western europe recent developments and perspectives
Aquatic Living Resources, 2001Co-Authors: Patrick Williot, L. Sabeau, J. Gessner, G. Arlati, P. Bronzi, T. Gulyas, P. BerniAbstract:Sturgeon production in Western Europe originating from aquaculture in 1999 was approximately 1 300 t revealing an increasing trend. Three species represent 95 % of the annual production: white sturgeon (Acipenser transmontanus) 43 %, Siberian sturgeon (Acipenser baerii) 34 %, and Adriatic sturgeon (Acipenser naccarii) 18 %. The remainder is provided by various species including hybrids. The main countries in decreasing order of production are Italy, France, Spain, Germany and Poland. Fish are fed commercial formulated diet. The most significant changes in the sturgeon industry during recent years have been in the ownership of farms, in the emergence of the pond as a production system, and in the increasing caviar production from farmed sturgeon. In 1999, the production of farmed caviar from France and Italy, originating from Siberian and white sturgeon, respectively was close to 6 t. The number of active sturgeon farms in Western Europe is estimated to be approximately thirty, half of which are hatcheries. This paper presents different strategies and management approaches in sturgeon production and caviar processing. The potential caviar market and its dynamics are assessed and likely changes are discussed. Finally, some of the scientific investigations needed to improve and support this development are highlighted. Five different fields are distinguished: biological reserve, genetics, reproduction, farming, and quality of end products. © 2001 Ifremer/CNRS/INRA/Cemagref/Editions scientifiques et medicales
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molecular cytogenetic analysis of the karyotype of the european atlantic sturgeon Acipenser sturio
Heredity, 1999Co-Authors: J Tagliavini, Massimo Lanfredi, Milvia Chicca, Leonardo Congiu, R Rossi, Patrick Williot, F FontanaAbstract:Molecular cytogenetic analysis of the karyotype of the European Atlantic sturgeon, Acipenser sturio
Olivier Chassaing - One of the best experts on this subject based on the ideXlab platform.
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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.
Dorota Fopp-bayat - One of the best experts on this subject based on the ideXlab platform.
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Meiotic gynogenesis revealed not homogametic female sex determination system in Siberian sturgeon (Acipenser baeri Brandt).
Aquaculture, 2010Co-Authors: Dorota Fopp-bayatAbstract:Meiotic gynogenesis was induced in a Siberian sturgeon (Acipenser baeri Brandt) by heat shock after egg activation with UV-irradiated sperm of a hybrid Siberian sturgeon × Russian sturgeon (Acipenser gueldenstaedti Brandt). Microsatellite DNA analysis was applied for verification of unipaternal inheritance in the gynogenetic diploid group of fish. All the analyzed gynogenetic diploids possessed only maternal genotype in the examined experimental group of fish. Histological analysis of gonads of 50 gynogenetic diploids, obtained from one family, showed 81% of females and 19% of males. The observed sex ratio suggested that the Siberian sturgeon does not have a female homogametic sex determination system.
