en Stock assessment Stock assessment پژوهشي Orginal research papers <div style="text-align: justify;"><span style="font-size:11pt"><span style="line-height:120%"><span style="font-family:Calibri,sans-serif"><span style="font-size:12.0pt"><span style="line-height:120%"><span new="" roman="" style="font-family:" times=""><span style="color:black">Based on the climate hydrology, ecological biogeography, and land&ndash;sea interaction relationships, Vietnamese coastal waters can be separated into three coastal zones. In this study, we analyzed the <i>Johnius carouna </i></span></span></span></span><span style="font-size:12.0pt"><span style="line-height:120%"><span new="" roman="" style="font-family:" times=""><span style="color:black">(Cuvier, 1830)<b> </b></span></span></span></span><span style="font-size:12.0pt"><span style="line-height:120%"><span new="" roman="" style="font-family:" times=""><span style="color:black">shape of sagittae from several areas along the Vietnamese coast. The morphometric characters of the otoliths were used to identify stock among the fish of different geographic areas. A multistatistics analysis of otolith shapes was applied to estimate the differences between the three regions. Based on the shape indices, wavelet transform <a name="_Hlk97020840">and Elliptic Fourier Descriptors</a> (EFD) have signals for division into three groups of otolith shapes (discriminant analysis for wavelet transform: Wilks=0.065, </span></span></span></span><i><span style="font-size:12.0pt"><span style="line-height:120%"><span new="" roman="" style="font-family:" times=""><span style="color:black">p</span></span></span></span></i><span style="font-size:12.0pt"><span style="line-height:120%"><span new="" roman="" style="font-family:" times=""><span style="color:black"><0.001 training misclassification error 9.8%; discriminant analysis EFD:&nbsp; Wilks=0.059, </span></span></span></span><i><span style="font-size:12.0pt"><span style="line-height:120%"><span new="" roman="" style="font-family:" times=""><span style="color:black">p</span></span></span></span></i><span style="font-size:12.0pt"><span style="line-height:120%"><span new="" roman="" style="font-family:" times=""><span style="color:black"><0.001 accuracies of the classification equal 93.75%; analysis of variance on shape indices: </span></span></span></span><i><span style="font-size:12.0pt"><span style="line-height:120%"><span new="" roman="" style="font-family:" times=""><span style="color:black">p</span></span></span></span></i><span style="font-size:12.0pt"><span style="line-height:120%"><span new="" roman="" style="font-family:" times=""><span style="color:black"><0.05) of the otoliths for the three locations. This study inferred that two distinct stocks were identified, namely Cat Ba and Tho Chu. The individuals from the central zone (Phu Yen) may be a mixing zone between the north and the south, with two possible populations of Cat Ba and Tho Chu.</span></span></span></span></span></span></span></div> Johnius carouna, Caroun croaker, Discriminant analysis, Wavelet transform, East Vietnam Sea. 864 879 http://jifro.ir/browse.php?a_code=A-10-4444-1&slc_lang=en&sid=1 Q.T. Vu vuquyetthanh@gmail.com 100319475328460046438 100319475328460046438 Yes Vietnam-Russia Tropical Center V.D. Tran dattran1069@gmail.com 100319475328460046439 100319475328460046439 No Vietnam-Russia Tropical Center V.Q. Nguyen fishhio@gmail.com 100319475328460046440 100319475328460046440 No Vietnam Academy of Science and Technology