Mitochondrial DNA variation and population genetic structure of white shrimpFenneropenaeus indicusalong the coastal belt of Sri Lanka

Abstract

Received 31 May 2010; Accepted 17 November 2010 Abstract - The white shrimp (Fenneropenaeus indicus) is an ecologically and economically important penaeid species, widely distributed in the Indo-Pacific region. To obtain information on the genetic variation and population structure of F. indicus, sequencing analysis was conducted on a fragment of cytochrome oxidase subunit I (COI) of the mito- chondrial DNA. Individuals (n = 217) from eight locations covering four main geographic regions along the coastal belt of Sri Lanka were analysed. The sequences, a 602-base pairs (bp) fragment in length, revealed high haplotype and nucleotide diversity that yielded 82 haplotypes. A mismatch analysis produced a unimodal distribution of pairwise differences between haplotypes, consistent with a historic rapid population expansion. Little or no genetic differentia- tion was observed between most samples, although genetic distances based on pairwise differences between haplotypes started to increase when geographic distances exceeded about 130 km. A population in Bundala (southeast) had lower diversity and was genetically differentiated from the others. This information could be important for the sustainable management and utilization of this resource.