TY - JOUR ID - 2465 TI - Effect of human chorionic gonadotropin on sexual maturation, sex steroids and thyroid hormone levels in Caspian lamprey (Caspiomyzon wagneri Kessler, 1870). JO - Caspian Journal of Environmental Sciences JA - CJES LA - en SN - 1735-3033 AU - Abedi, M. AU - Mojazi Amiri, B. AU - Abdoli, A. AU - Javanshir, A. AU - Benam, S. AU - Namdarian, A. AD - Department of Fisheries, Faculty of Natural Resources, University of Tehran, Karaj, Iran AD - Department of Biodiversity and Ecosystem Management, Environmental and Research Institute, Shahid Beheshti University, Iran Y1 - 2017 PY - 2017 VL - 15 IS - 3 SP - 237 EP - 247 KW - Lamprey KW - Caspian Sea KW - Induced reproduction KW - Hormonal changes DO - 10.22124/cjes.2017.2465 N2 - The objective of this study was to determine the effect of human chorionic gonadotropin (hCG) on sexual maturation, plasma sex steroids (17β-estradiol, E2 and 17α-hydroxy progesterone (17α OHP)) and thyroid hormones (triiodothyronine, T3 and thyroxin, T4) levels in upstream - migrating Caspian lamprey. During the experiment, 36 fish (24 females and 12 males) in  spring 2013 and 36 fish (24 females and 12 males) in  fall 2013 were collected from the Shirud River estuary in Mazandaran Province, the Southern Caspian Sea during their upstream migration to the freshwater. All fish were injected with hCG at the doses of 1000, 1500 and 2000 IU.kg BW-1. The injection was a two - step process (50% of hormone in each step) by 12 h interval. After the first injection, fish were retained in the cages in the river beds and 24 hours after the second injection, fish were checked for egg and sperm release after mild abdomen pressure. Blood samples were taken for determining sex steroid levels. Results showed that hCG hormone injections caused increase in migration of germinal vesicle in the oocyte of female and sperm release in males. Significant differences were found in the serum E2 and 17α-OHP levels in hCG - injected fish compared to the control. However, no significant differences were found in serum T3 and T4 levels in the hCG - injected fish. According to the results, the appropriate hCG dosage to induce the reproduction acceleration in Caspian lamprey is 1500-2000 IU.kg BW-1. UR - https://cjes.guilan.ac.ir/article_2465.html L1 - https://cjes.guilan.ac.ir/article_2465_8a6fa2b296d064b089e61124d580d4e6.pdf ER -