Falahatkar Bahram, Nargesi Erfan Akbari, Efatpanah Iraj, Żarski Daniel
Fisheries Department, Faculty of Natural Resources, University of Guilan, Sowmeh Sara, Guilan, Iran; Department of Marine Sciences, The Caspian Sea Research Basin Center, University of Guilan, Rasht, Guilan, Iran.
Fisheries Department, Faculty of Natural Resources, University of Guilan, Sowmeh Sara, Guilan, Iran.
Anim Reprod Sci. 2022 Oct;245:107055. doi: 10.1016/j.anireprosci.2022.107055. Epub 2022 Aug 19.
The aim of the present study was to evaluate the effectiveness of human chorionic gonadotropin (hCG) in stimulation of second spermiation in already reproduced pikeperch males during the same spawning season. Fish (mean weight 919.9 ± 236.9 g) were divided into the control saline-injected group, and two groups injected with 200 and 400 IU hCG/kg body weight. Forty-eight hours following injection (at a temperature of 16.7 °C) the percentage of fish producing useable amounts of semen increased from 30% in the control group up to 80% in the treated fish and the highest volume of semen was recorded in fish treated with 400 IU/kg BW hCG. Spermatocrit (50.7 ± 9.1%) and sperm concentration (17.5 ± 5.0 × 10 spermatozoa/mL) were significantly higher in control fish than those recorded in hCG-treated fish (24.8 ± 7.7% and 8.1 ± 2.4 × 10 spermatozoa/mL in 200 IU/kg; 32.3 ± 17.6% and 10.9 ± 7.5 × 10 spermatozoa/mL in 400 IU/kg). No significant differences were observed between the groups with respect to sperm motility (as a spermatozoa activity time and percentage); however, a change in plasma alkaline phosphatase activity was found in the group injected with 400 IU/kg of hCG. The lack of significant differences in plasma metabolites and cortisol between control and hCG-treated fish indicated that the hCG had no effect on the stress response. Testosterone levels were significantly increased in the hCG-treated fish, whereas no significant differences in 17β-estradiol were recorded. No differences between the groups in plasma levels of thyroid hormones suggested lack of hCG-induced effect on hypothalamus-pituitary-thyroid axis. The results of this study demonstrated that the spermiation of already reproduced pikeperch males could be induced by hCG during the same spawning season. Based on the results on semen volume and concentration, injection with hCG could improve the efficiency of pikeperch reproduction to reduce the number of brooders and costs of juvenile pikeperch production.
本研究的目的是评估人绒毛膜促性腺激素（hCG）对已繁殖过的梭鲈雄鱼在同一繁殖季节诱导第二次排精的有效性。将鱼（平均体重919.9±236.9克）分为对照组（注射生理盐水）和两组分别注射200和400国际单位/千克体重hCG的处理组。注射后48小时（温度为16.7°C），产生可用量精液的鱼的百分比从对照组的30%增加到处理组鱼的80%，且在注射400国际单位/千克体重hCG处理的鱼中记录到最高精液量。对照组鱼的精子密度（50.7±9.1%）和精子浓度（17.5±5.0×10个精子/毫升）显著高于hCG处理组鱼（200国际单位/千克组为24.8±7.7%和8.1±2.4×10个精子/毫升；400国际单位/千克组为32.3±17.6%和10.9±7.5×10个精子/毫升）。各组在精子活力（作为精子活动时间和百分比）方面未观察到显著差异；然而，在注射400国际单位/千克hCG的组中发现血浆碱性磷酸酶活性有变化。对照组和hCG处理组鱼在血浆代谢物和皮质醇方面无显著差异，表明hCG对应激反应无影响。hCG处理组鱼的睾酮水平显著升高，而17β-雌二醇未记录到显著差异。各组血浆甲状腺激素水平无差异，表明hCG对下丘脑-垂体-甲状腺轴无诱导作用。本研究结果表明，已繁殖过的梭鲈雄鱼在同一繁殖季节可被hCG诱导排精。基于精液量和浓度的结果，注射hCG可提高梭鲈繁殖效率，以减少亲鱼数量和幼鱼生产成本。
