Iranian Journal of Fisheries Sciences

en Research Article: Gametogenesis and reproduction cycle of the sea urchin Echinometra sp. from the Northern Persian Gulf based on the histology and gonad indices Biology & physiology Biology & physiology پژوهشي Orginal research papers The sea urchin Echinometra sp. is a native species of the Persian Gulf. Despite its great ecological value, the reproductive biology of this animal has not been studied in the Persian Gulf. Therefore, the present study aimed to describe the annual reproductive cycle of this species from the Persian Gulf via gonadal tissue indicators. In the present study, approximately 120 males and females were collected monthly (approximately 10 samples/month) between February 2023 and January 2024 from the tidal zone of the Bushehr coast of the Northern Persian Gulf. The sex of the samples, different stages of sexual maturity, mean gonadal index, gonad coverage area, frequency of oocytes in different stages, and diameter of the oocytes were determined via gonadal tissue sections. Six stages of sexual maturity, including the repair, growth, premature, mature, spawning, and reabsorption stages, were detected in the gonads of the males and females. Only one annual reproductive cycle was identified for this species. In females, this cycle included a period of gametogenic activity (from December to June) and a spawning period of several months (from June to August), followed by a long period of recovery and sexual rest (from August to the end of December). In males, gametogenesis starts in October and lasts until the end of May. This period was followed by the spawning period from June to August and then a short period of recovery and sexual rest (September). It seems that a decrease in seawater temperature stimulates the start of the gametogenic cycle and high seawater temperatures stimulate the release of gametes of Echinometra sp. in Bushehr. In general, Echinometra sp. has a specific spawning season from late spring to early summer and is not able to spawn throughout the year. Sea urchin, Echinoderms, Reproductive biology, Persian Gulf, Echinometra sp. 819 835 http://jifro.ir/browse.php?a_code=A-10-57-8&slc_lang=en&sid=1 H. Ghanavati hadisghanavati22@yahoo.com 100319475328460056835 100319475328460056835 No Department of Marine Biology, Faculty of Marine Science and Oceanography, Khorramshahr University of Marine Science and Technology, Khorramshahr, Iran. N. Salamat salamatnegin@yahoo.com 100319475328460056836 100319475328460056836 Yes Department of Marine Biology, Faculty of Marine Science and Oceanography, Khorramshahr University of Marine Science and Technology, Khorramshahr, Iran. M.A. Salari aliabadi MAsalariali@yahoo.com 100319475328460056837 100319475328460056837 No Department of Marine Biology, Faculty of Marine Science and Oceanography, Khorramshahr University of Marine Science and Technology, Khorramshahr, Iran. A. Fakhri alifakhrii@gmail.com 100319475328460056838 100319475328460056838 No Department of Fisheries and Marine Sciences, Persian Gulf Research Institute, Persian Gulf University, Bushehr, Iran. A. Rezaie annahitrezai@gmail.com 100319475328460056839 100319475328460056839 No Department of Pathobiology, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran