Genetic Analysis of a Population of Atlantic salmon (Salmo salar, L.)in the Rhine System
The present study was developed under the guidelines of a regional project to support the management of the anadromous salmonids in the Rhine, particularly the reintroduction of the Atlantic salmon (Salmo salar, L.) The main aim was to assign the salmons ascending to the Iffezheim lock to salmons us...
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| Format: | Doctoral or Postdoctoral Thesis |
| Language: | English |
| Published: |
2009
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| Online Access: | https://archiv.ub.uni-heidelberg.de/volltextserver/9840/ https://archiv.ub.uni-heidelberg.de/volltextserver/9840/1/PHD_thesis_Laura_Papa.pdf https://doi.org/10.11588/heidok.00009840 https://nbn-resolving.org/urn:nbn:de:bsz:16-opus-98405 |
| Summary: | The present study was developed under the guidelines of a regional project to support the management of the anadromous salmonids in the Rhine, particularly the reintroduction of the Atlantic salmon (Salmo salar, L.) The main aim was to assign the salmons ascending to the Iffezheim lock to salmons used for reintroduction in the Rhine. It was analysed if such an assignment was reasonably possible. Furthermore, we wanted to find out if an established Rhine population already exists. The Ph.D. study started in April 2005 and was supported by voluntary field workers who sampled and checked the fish ladder at Iffezheim (Landesfischereiverband Baden). Genotypes, based on the analysis of polymorphic microsatellite loci, of the sampled year-classes from 2002 to 2005 inclusive, have been analyzed, and referenced to suitable outgroup populations. An overall amount of 180 salmon samples have been analyzed (65 from Rhine/Germany, 22 from Burrishoole/Ireland, 50 from Allier/France, 28 from Ätran/Sweden and 15 from Lagan/Sweden). An allozyme analysis was performed in order to identify individuals which eventually were misidentified during the sampling with brown trout or hybrids from the two species. 11 fishes out of the 304 analyzed turned out to be misidentified trouts given as salmons. Microsatellites genotyping involved sixteen primers, two STR (Short Tandem Repeat) amplified for two loci, and nine loci (SSOSL85, SSOSL311, STR15, Ssa171, Ssa402*, Ssa402**, Ssa408, Ssa202 and Ssa411). Genetic similarities have been evaluated by means of population genetics and forensic assignment statistics of individuals. Analysed individuals were all in HWE (Hardy-Weinberg Equilibrium). Heterozygosity ranged from 0.60 to 0.79. Analysis of allele frequencies revealed a heterozygotes deficiency and a significant genetic drift. A Whalund effect was supposed to lie behind this homozygote excess. By the bottleneck analysis no evidence of recent reduction in population size has been observed in the Rhine subpopulation according to TPM ... |
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