en Biology & physiology Biology & physiology پژوهشي Orginal research papers <p>In this study, otolith morphology and otolith contour from big-scale sand smelt, <em>Atherina boyeri</em> were analyzed in Lake Eğirdir and Lake İznik (natural lakes), and Hirfanlı Dam Lake (artificial lake). The otolith contour and sixteen otolith morphological characters such as width, depth, shape, sulcus acusticus shape, ostium, cauda, rostrum size-shape, and thickness, antirostrum size-shape, and thickness, anterior and posterior regions, mesial and lateral surfaces were successfully investigated for three total length groups of <em>A. boyeri</em> inhabiting the lakes. Intraspecific variation in rostrum shape, rostrum size, rostrum thickness, antirostrum, anterior region, mesial and lateral surfaces were observed for the three total length groups of three <em>A. boyeri</em> populations. In the three different lakes, saccular otolith surface morphology of <em>A. boyeri</em> was detected such as a flattened surface for Lake Eğirdir, rough surface for Lake İznik, and relatively smooth surface for Hirfanlı Dam Lake using the Scanning Electron Microscope. The otolith contours showed noticeable differences in the three total length groups of <em>A. boyeri</em> from the different lakes. Intraspecific variability of the otolith characters and morphology consisting of the otolith surface morphology and otolith contour were presented and compared for the three total length groups of the <em>A. boyeri </em>from the different lakes.</p> Morphology, Intraspecific, Atherina boyeri, Invasive, Natural and artificial lakes 635 645 http://jifro.ir/browse.php?a_code=A-10-1947-3&slc_lang=en&sid=1 S YEDİER serdar7er@gmail.com 100319475328460030858 100319475328460030858 No Department of Molecular Biology and Genetics, Ordu University, Ordu, Turkey D Bostanci deryabostanci@gmail.com 100319475328460030859 100319475328460030859 Yes Department of Molecular Biology and Genetics, Ordu University, Ordu, Turkey S Kontaş sedakontas@gmail.com 100319475328460030860 100319475328460030860 No Department of Molecular Biology and Genetics, Ordu University, Ordu, Turkey G Kurucu gulsahkeskinn@gmail.com 100319475328460030861 100319475328460030861 No Department of Molecular Biology and Genetics, Ordu University, Ordu, Turkey M Apaydin Yağci meralyagci@gmail.com 100319475328460030862 100319475328460030862 No Fisheries Research Station, Eğirdir, Isparta, Turkey N Polat npolat@omu.edu.tr 100319475328460030863 100319475328460030863 No Department of Biology, 19 Mayıs University, Samsun, Turkey