Theme E: Interactions between wild and released animals and their ecological and genetic implications
27. GENETIC INTERACTIONS BETWEEN WILD AND HATCHERY RED SEA BREAM CONFIRMED BY MICROSATELLITE GENETIC MARKERS
Blanco Gonzalez1, Masaki Aritaki2 and Nobuhiko Taniguchi1
1The Research Institute of Marine Bioresources of Fukuyama University 452-10 Innoshima- Ohama, Onomichi 722-2101, Japan
2Coastal Fisheries and Aquaculture Division, Seikai National Fisheries Research Institute, Fisheries Research Agency, 1551-8, Taira-machi, Nagasaki 851-2213, Japan
orgas_99@yahoo.es
Millions of red sea bream juveniles have been annually released throughout the Japanese Archipelago over the last decades. Releases have contributed to the harvestable stocks of this commercially and culturally important species; however, little emphasis has been placed upon addressing introgression between wild and hatchery-reared fish in a large-scale. In contrast to freshwater or low-range migratory species, red sea bream in Japan comprises a single “large” panmictic stock where specimens undertake long-distance migrations. This fact makes difficult to elucidate the magnitude of the contribution of enhancement programs, requiring large number of high-polymorphic markers such as microsatellites. In this study, twenty microsatellite markers were genotyped to overcome the limitations and characterize the genetic profiles of 1098 red sea bream collected at 16 locations and 4 hatchery strains. The analysis reinforced the hypothesis that red sea bream in Japan comprises a single panmictic stock. However, evident signs of genetic differentiation, likely related to the releasing history of the species, have been detected at two locations. Therefore, these results stress the need to monitor and revise the effectiveness of large-scale releases in long-term, including the genetic interaction between wild and hatchery specimens.
Fig. 1. MDS plot based on pairwise genetic differentiation (FST) among samples.
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