The Lake Kronotskoe Kokanee Oncorhynchus nerka Division Based on the Microsatellite Data

The diversity of eight microsatellite DNA loci was analyzed to assess the contemporary level of reproductive isolation between the sockeye salmon with lower numbers (sparse) and higher numbers (dense) of gill rakers cohabiting the landlocked Lake Kronotskoe and its tributaries (Kamchatka Peninsula). We found a significant difference among three groups: the sparsely-rakered fish with lacustrine spawning, the sparsely-rakered fish with riverine spawning and the densely-rakered fish with both types of spawning. The interannual and spatial genetic structure of the three fish groups was found to remain stable, and the sparsely-rakered fish with riverine spawning exhibited a decreased level of microsatellite diversity and heterozygosity.