Reduced Genetic Diversity in a Breeding Population of the Chinese Sucker (Myxocyrinus asiaticus Bleeker) as Revealed by DNA Fingerprinting

ABSTRACT

Artificial breeding for endangered species and subsequent reintroduction are often implemented as conservation strategies, but the reliability of the measures in avoiding the extinction of wild populations is questionable. In this study, we demonstrated reduced genetic variability in a farmed population of the Chinese sucker (Myxocyrinus asiaticus) by DNA fingerprinting. Direct parameters (genetic variability, hypervariable loci and heterozygosity) and indirect parameters (band-sharing coefficient and allelic frequency) revealed that artificial breeding of this species caused the reduction of genetic diversity below historic levels, which predicts reduced individual fitness and lower population adaptability than in historic individuals. As a result, conservation efforts, including the introduction of parent fish from natural waters into farmed populations, are needed to improve the genetic structure of farmed breeding stock and to maximize chances for persistence of the whole species after subsequent reintroduction of farmed individuals.