en Biotechnology Biotechnology پژوهشي Original research papers <p style="margin-bottom:0cm;margin-bottom:.0001pt;text-align:justify; line-height:150%">Echinoids were collected at depth of 0-5 m from coastal water of Larak Island, the Persian Gulf in January 2016. Soft tissues of the animal including peristome, peritoneum, gills, podium, ampulla, axial organ, gonads and food canal were taken and fixed in %10 formalin. Five micron sections were stained by hematoxylin and eosin method and studied under light microscope. The anatomy and histology of organs including peristome, peritoneum, gills, podium, ampulla, axial organ, gonads and food canal were investigated. In oral view, peristome, mouth, teeth, gills, spines, and pedicellariae were the six major compartments.&nbsp;Aboral view was seen as a round shape consisted of tube feet, spines, pedicellariae, madreporite, genital plate, ocular plate and anus. In both oral and aboral view seven types of spines and five types of pedicellariae were reported. Histological evaluation showed the organization of their layers and cells. In this study some anatomical and histological features of the Persian Gulf <em>Echinometra</em><em> mathaei</em> were characterized. The data presented in this paper could be illuminating the path for marine biologists, anatomists, and histologists to use this creature in their desired research areas, basic or industrial approaches.<br> &nbsp;</p> Sea urchin, Echinometra mathaei, Anatomy, Histology, The Persian Gulf 1 27 http://ijaah.ir/browse.php?a_code=A-10-223-1&slc_lang=en&sid=1 F Piryaei piryaei.fatemeh@yahoo.com 10031947532846002024 10031947532846002024 No Department of Marine Biology, Graduate school of Marine Science and technology, Science and Research Branch, Islamic Azad University, Tehran, Iran P Ghavam Mostafavi gh.mostafavi@gmail.com 10031947532846002025 10031947532846002025 No Department of Marine Biology, Graduate school of Marine Science and technology, Science and Research Branch, Islamic Azad University, Tehran, Iran D Shahbazzadeh shahbazzadeh@yahoo.com 10031947532846002026 10031947532846002026 No Venom and Biotherapeutics Molecules Lab, Medical Biotechnology Dept, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran K Pooshang Bagheri kamranpb@gmail.com 10031947532846002027 10031947532846002027 Yes Venom and Biotherapeutics Molecules Lab, Medical Biotechnology Dept, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran