Increased frequency in the Ikehara Reservoir population and dispersion to other lakes and ponds of the genes originating from the Florida subspecies of the largemouth bass

Abstract

The original population of the Ikehara Reservoir consisted of a subspecies of the largemouth bass, Micropterus salmoides salmoides. In 1988, another subspecies, M. s. floridanus, originating from Florida was transplanted there. In 1996/97 a genetic study was made on the population in regard to their mitochondrial (mt) DNA with the result that M. s. floridanus was detected from 56.8% of fish. We re-examined the population in 2003 and found that fish having the mtDNA originating from M. s. floridanus accounted for a significantly higher percentage than before (86.7%). Moreover, fish having the mtDNA originating from M s. floridanus were found from other lakes and ponds in the Kinki District.