A MORPHOLOGICAL STUDY OF NATIVE STURGEON Acipenser sturio IN SPAIN, AND RECENT RECORDS OF EXOTIC SIBERIAN STURGEON

RAPD analysis was utilised to differentiate six sturgeon species.Amplifications with different primers gave reproducible electrophoretic patterns which could be regarded as a data-set consisting of monomorphic and polymorphic characters.Our results provided evidence that RAPD markers can be used to discriminate between species of sturgeons and indicate new possible systematic considerations within the examined taxa.Some of the species-specific markers were isolated and cloned in order to provide effective molecular probes to distinguish the different sturgeons species.The present study investigated molecular markers to identify the following species of sturgeons and to study their systematic relationships: Huso huso Linnaeus, Acipenser naccarii Bonaparte, A .baerii Brandt, A.r gueldenstaedtii Brandt, A .transmontanus Richardson and A ruthenus Linnaeus.To this end, we applied a molecular technique based on the Polymerase Chain Reaction (PCR) known as Random Amplified Polymorphic DNA analysis.This technique provides genetic markers, derived from priming sites randomly distributed throughout the genome, inherited in a mendelian fashion.These markers allow analysis of complex genomes, like eukaryotes, without prior knowledge of the DNA sequence.From a previous screening of a wide set of primertemplate combinations, we chose eight primers that gave a high number of polymorphic markers and a highly significant percentage of comigrating bands, assumed to be monomorphic characters.The selected primers were then employed to verify their reproducibility in independent experiments, the most important requirement for any RAPD analysis.The method has proven valuable as it is able to distinguish the different species These markers were isolated, cloned and sequenced, providing molecular data to