Evaluation of translocation impacts on genetic patterns in farmed and naturalized populations of Mytilus galloprovincialis along the China coast: clues from mitochondrial cytochrome c oxidase I sequences

Abstract

As an introduced species, Mytilus galloprovincialis has developed into self-sustaining naturalized populations and has been widely cultivated in northern China. The M. galloprovincialis aquaculture industry wholly depends on the movement of naturalized juveniles onto farms. It is, therefore, necessary to understand the genetic effect of continuous spats’ translocation. This study divided 12 localities of M. galloprovincialis along the China coast into three types of populations—farmed, naturalized adjacent farmed, and isolated—to investigate the genetic variation and differentiation. The genetic variability is reflected by haplotype diversity, nucleotide diversity, and the mean number of pairwise differences expressed as farmed populations > naturalized adjacent farmed populations > isolated populations. The Hierarchical analyses and Mantel-test indicated slight divergence between farmed and naturalized populations, northern and southern populations. The farmed and naturalized populations clustered into two separate categories in the neighbor-joining tree except two anthropogenically intervened localities. The present results suggest that the translocation practice positively affected genetic variability and played a vital role in shaping genetic composition. The information obtained in this study provides new insights into the impacts of the translocation culture model of marine mollusks.