한국산 남방짱뚱어(Scartelaos gigas) 및 짱뚱어(Boleophthalmus pectinirostris)의 지역 간 형태 및 유전변이

Abstract

The mudskippers, Scartelaos gigas and Boleophthalmus pectinirostris, are amphibious gobiid fishes which mainly inhabit in the mudflat. These two species have been economically important fishes in east Asia. Especially, Boleophthalmus pectinirostris is commercially exploited in Korea, Japan, China and Taiwan. The population density of Korean mudskippers have been decreased because of overfishing, habitat destruction and pollution etc. For the investigation of genetic and morphological divergence among several local populations, we examined morphological and genetic variations of two species. Multivariate methods were used to compare 6 meristic and 16 morphometric characters of Scartelaos gigas and Boleophthalmus pectinirostris. PCA (Principal Component Analysis) and CDA (Canonical Discriminant Analysis), based on 16 morphometric characters showed that scores plotted on axes 1-2 and 2-3 separated the three local populations groups in Scartelaos gigas (Suncheon, Shinan, Jangheung & Yeonggwang). In case of Boleophthalmus pectinirostris, It is also divided into three local populations (Suncheon, Shinan, Kangjin). These results suggest that the both two Korean mudskipper species may comprise at least three local populations, respectively. The genetic diversity and population genetic structure of Scartelaos gigas were examined with a nucleotide sequence analysis of a 548bp fragment of mirochondrial DNA (mtDNA) control region gene in 105 individuals collected from four local populations (Suncheon, Shinan, Jangheung, Yeonggwang). 36 haplotypes were defined. The observed hapotypes had a shallow haplotype genealogy and no geographical association (FST = -0.0120 ~ 0.0235, P>0.05). And genetic diversity and genetic population structure of Boleophthalmus pectinirostris were examined with a 565bp fragment of mtDNA control region in 76 individuals collected from three local populations (Suncheon, Shinan, Kangjin). 25 haplotypes were defined. There are no geographical association among local populations (FST = -0.0026 ~ 0.0158, P>0.05). Most of populations of two species had high haplotype diversity and low nucleotide diversity and significant negative values for Fu's Fs, suggesting rapid, recent population growth from an ancestral population and sudden population expansion. We used five microsatellite markers to detect genetic diversity in Korean Boleophthalmus pectinirostris. Significant differentiation was found between three local populations (FST = 0.0456 ~ 0.0621, P<0.001). The results obtained in this study have valuable genetic information for the management and conservation of Scartelaos gigas and Boleophthalmus pectinirostris populations.