en Ecology Ecology پژوهشي Orginal research papers <span style="font-size:11pt"><span style="line-height:120%"><span style="tab-stops:0in 137.25pt 187.5pt 237.75pt"><span style="text-autospace:none"><span style="font-family:Calibri,sans-serif"><span lang="TR" style="font-size:12.0pt"><span style="line-height:120%"><span new="" roman="" style="font-family:" times=""><span style="color:black">Gastropods are considered as the main molluscs of rocky shores and often show marked zonation patterns both horizontally and vertically. Biodiversity and distribution of gastropods were investigated at 8 stations on rocky shores of Qeshm Island during the coldest and warmest months January and &nbsp;August, respectively, in 2018.</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">In the present study,</span></span></span></span><span lang="TR" style="font-size:12.0pt"><span style="line-height:120%"><span new="" roman="" style="font-family:" times=""><span style="color:black"> 35 gastropod species were identified. The highest frequency of gastropod (550&plusmn;345) was observed at S2 station (Tula 2) and the lowest one was observed at S8 station (Naz Island) (273&plusmn;83.70). <i>Planaxis sulcatus</i> was found as the dominant species at all stations (%55.76). The results of the 3-way permutational (MANOVA) test showed that the species&rsquo; structures of the gastropod community are different at various stations and during sampling months. The results of the nMDS test confirmed these differences in the structure and species composition of the gastropod population during two months. The highest diversity (Shannon index: 3.13) and species richness (Margalef index: 4.53) was observed at the S2 station and the lowest diversity (Shannon index: 2.73, Margalef index: 3.03) was observed at the S8station. According to the results of the <em>SIMPER </em>test, the highest percentage of participation in Bray-Curtis dissimilarity between the two months in summer and winter and at different sampling stations in terms of species density was related to <i>Planaxis sulcatus</i>. The structure of gastropod population at the studied stations can be influenced by the factor of seasonal changes.</span></span></span></span></span></span></span></span></span> Biodiversity, Spatial Distribution, Rocky shores, Qeshm Island, Persian Gulf 1298 1315 http://jifro.ir/browse.php?a_code=A-10-3450-3&slc_lang=en&sid=1 N. Gholinezhad nonosh_gh@yahoo.com 100319475328460046550 100319475328460046550 No Faculty of Marine Science and Technology, North Tehran Branch, Islamic Azad University (IAU),Tehran, Iran A. Ashja Ardalan ariaashja@gmail.com 100319475328460046551 100319475328460046551 Yes Faculty of Marine Science and Technology, North Tehran Branch, Islamic Azad University (IAU),Tehran, Iran M. Malek masoumeh.malek@gmail.com 100319475328460046552 100319475328460046552 No School of Biology, College of Science, University of Tehran, Tehran, Iran