TITLE:
Genetic Variability and Reproduction Structure of Corbicula japonica in Major Fishing Brackish Lakes in Japan
AUTHORS:
Tsudzumi Mito, Tomomi Tanaka, Futoshi Aranishi
KEYWORDS:
Corbicula japonica, Brackish Lakes, Genetic Diversity, Reproduction Structure, Cytochrome Oxidase c Subunit I Gene
JOURNAL NAME:
Open Journal of Marine Science,
Vol.4 No.3,
July
31,
2014
ABSTRACT: Corbicula japonica is the best-known bivalve inhabiting widely in
brackish estuaries and lakes in Japan. Although this species has been most
commercially important species of inland fisheries in Japan, the gradual
decline in its production over 40 years caused not only economic problems in
fishery industry but also ecological disturbances in biodiversity conservation.
The aim of this study was to evaluate the reproduction structure of C. japonica populations in major
fishing brackish lakes based on the genetic diversity inferred by mitochondrial
DNA sequence analysis of the cytochrome oxidase c subunit I gene. Of a total of 188 C. japonica individuals collected in Lakes Shinji, Jusan, Ogawara
and Abashiri, 25 haplotypes were obtained, and only the haplotype HT01 was
apparent with relatively high abundance in all lakes. Minimum spanning network
analysis of haplotypes showed different population structures between Lake
Shinji and Lakes Jusan, Ogawara and Abashiri. In addition, pairwise population
genetic distance FST and ΦST values were significantly
higher in Lake Shinji than Lakes Jusan, Ogawara and Abashiri. The mismatch
distribution analysis showed unimodal profile for Lakes Jusan and Ogawara and
bimodal profile for Lakes Shinji and Abashiri. Those results indicate a recent
population expansion in all lakes, and Lakes Shinji and Abashiri and Lakes
Jusan and Ogawara maintained continuous reproduction structure and suffered to
rapid population growth, respectively.