en Biology & physiology Biology & physiology پژوهشي Orginal research papers <span lang="TR" style="font-size:11.0pt"><span calibri="" style="font-family:">This study collected 27 Blenniid specimens of 10 species from intertidal and subtidal habitats in the Persian Gulf and Oman Sea. The specimens were preserved and taxonomically identified before the genomic DNA extraction. The COI marker was then amplified and sequenced. Additional sequences from related subfamilies were obtained from GenBank. Phylogenetic reconstruction was carried out using Bayesian and phenetic methods. The study aimed to evaluate the phylogenetic position of the newly studied specimens and reconstruct the phylogenetic relationships among representatives of the Blenniidae. The amplification of the COI marker for <i>Istiblennius edentulus</i> and <i>Salarias fasciatus</i> in Iran is a significant advancement in understanding phylogeny, genetic diversity, and evolutionary connections in the area. A phylogenetic analysis was conducted using molecular data from this study and previous research from the southern waters of Iran. The study revealed that the subfamilies Blenniinae and Salariinae are paraphyletic and two tribes, Parablenniini and Omobranchini, form monophyletic groups. <i>Istiblennius </i>is considered a paraphyletic genus. <i>Omobranchus mekranensis</i> and <i>O. punctatus</i> are in a closer relationship than <i>O. fasciolatus</i>, which is grouped at a further distance. The phylogenetic tree places <i>Ecsenius</i> in a monophyletic clade at the furthest distance from other taxa, suggesting it may warrant a separate tribe rather than a genus.</span></span> Fish taxonomy, Blenniinae, Salariinae, Salariini, Parablenniini, Omobranchini 849 860 http://jifro.ir/browse.php?a_code=A-10-2357-4&slc_lang=en&sid=1 M. Sharifiniya maryam.sharifiniya93@yahoo.com 100319475328460052630 100319475328460052630 No Department of Fisheries, Faculty of Natural Resources, University of Guilan, Sowmeh Sara, Iran H. Mousavi-Sabet mosavii.h@gmail.com 100319475328460052631 100319475328460052631 No Department of Fisheries, Faculty of Natural Resources, University of Guilan, Sowmeh Sara, Iran M.S. Alavi-Yeganeh alavi_tmu@yahoo.com 100319475328460052632 100319475328460052632 No Department of Marine Biology, Faculty of Natural resources and Marine Science, Tarbiat Modares University, Nur, Iran M. Ghanbarifardi mehdi.ghanbarifardi@science.usb.ac.ir 100319475328460052633 100319475328460052633 Yes Department of Biology, Faculty of Sciences, University of Sistan and Baluchestan, Zahedan, Iran