A conservation genetics perspective on supportive breeding: A case study of the common nase (<scp><i>Chondrostoma nasus</i></scp>)

Abstract Supportive breeding programmes are becoming increasingly crucial for the conservation of many declining freshwater fishes such as European common nase, Chondrostoma nasus . However, small relict populations genetically highly vulnerable, and supportive can have a detrimental impact on genetic composition cultured offspring (e.g. result inbreeding, drift, adaptation to captivity). This study monitored effects continuing programme nase by comparing diversity two wild spawning with respective progeny from captive originating spawners populations, considering variability, differentiation, inbreeding using nine microsatellite markers. Despite low one natural (River Sims) were remarkably different genetically, indicated pairwise analyses divergence ( F ST 0.028 0.070; Jost's D EST 0.080 0.205) discriminant analysis principal components. The mean number alleles allelic richness in captive‐bred also River Sims lower than Mangfall, signs detected = 0.106 bred 0.048 offspring). observed probably be attributed limited (two females three males) used breeding. In addition, results support previous evidence recruitment problems population, reduced hatching success. Collecting fertilized eggs rearing them captivity (repatriation approach) could an alternative stripping thereby improve populations.