fa <p><a name="OLE_LINK2"></a><a name="OLE_LINK1"><span style="font-family:times new roman,serif;"><span style="font-size:12.0pt;">The Japanese threadfin bream, </span></span><em><span style="font-family:times new roman,serif;"><span style="font-size:12.0pt;">Nemipterus </span></span><span style="font-family:times new roman,serif;"><span style="font-size:12.0pt;">japonicus</span></span></em><span style="font-family:times new roman,serif;"><span style="font-size:12.0pt;">, the most abundant and crucially economic </span></span><em><span style="font-family:times new roman,serif;"><span style="font-size:12.0pt;">Nemipterus</span></span></em><span style="font-family:times new roman,serif;"><span style="font-size:12.0pt;"> species</span></span><span style="font-family:times new roman,serif;"><span style="font-size:12.0pt;"> is widespread throughout the Indo-West Pacific. </span></span><span style="font-family:times new roman,serif;"><span style="font-size:12.0pt;">The species has been studied widely for various aspects but genetic studies are scanty.</span></span> <span style="font-family:times new roman,serif;"><span style="font-size:12.0pt;">This preliminary study contributes to the species phylogeography through the study of the genetic diversity and historical demography of <em>N. </em></span></span><em><span style="font-family:times new roman,serif;"><span style="font-size:12.0pt;">japonicus</span></span></em><span style="font-family:times new roman,serif;"><span style="font-size:12.0pt;"> populations from the Persian Gulf and Indo-West Pacific based on cytochrome c oxidase subunit I (COI)</span></span><span style="font-family:times new roman,serif;"><span style="font-size:12.0pt;"> gene sequence</span></span><span style="font-family:times new roman,serif;"><span style="font-size:12.0pt;">. Grouping</span> of the data into phylogenetic trees indicated that the </span><span style="font-family:times new roman,serif;"><span style="font-size:12.0pt;">Japanese threadfin bream</span></span><span style="font-family:times new roman,serif;"><span style="font-size:12.0pt;"> consists of </span></span></a><a name="OLE_LINK14"></a><a name="OLE_LINK13"><span style="font-family:times new roman,serif;"><span style="font-size:12.0pt;">two reciprocally monophyletic </span></span></a><span style="font-family:times new roman,serif;"><span style="font-size:12.0pt;">phylogroups with 2.3% net sequence divergence which may qualify as cryptic species: clade I, consists of two sub-clades (Ia and Ib) occurs in the Persian Gulf and Western India, and clade II, which is restricted to the South China Sea.</span></span><span style="font-family:times new roman,serif;"><span style="font-size:12.0pt;"> Historical and demographic hypotheses were raised to explain the observed phylogeographic pattern and population structure. Among the possible key mechanisms, sea level fluctuations driven by glacial episodes of the second half of the Pleistocene Epoch appear to have played an active role in initiating major phylogeographic separation. Apart from presumptive Pleistocene vicariance, a trend of increasing genetic differences with increasing geographic distance (i.e., isolation-by-distance) and regional differences in breeding season were also proposed as possible alternative scenarios. Since the baseline knowledge on the intraspecific genetic diversity and management and evolutionary significant units is the first step before any action to be taken, the basic findings provided by this research are particularly relevant to conservation efforts, fishery management and stock assessment</span></span></p> Nemipterus Japonicus, mtDNA, Phylogeography, Persian Gulf, Indo-West Pacific 587 604 http://jifro.ir/browse.php?a_code=A-10-61-5&slc_lang=fa&sid=1 S. Farivar s_farivar@sbu.ac.ir 100319475328460022698 100319475328460022698 Yes Z. Jalil-Piran 100319475328460022699 100319475328460022699 No F. Zarei 100319475328460022700 100319475328460022700 No H. Hosseinzadeh Sahafi 100319475328460022701 100319475328460022701 No