مشخصات پژوهش

عنوان	Evaluation of Egg Production and Sex Steroid Profiles in the Goldfish (Carassius auratus) During Four Consecutive Seasons
نوع پژوهش	مقاله چاپ‌شده در مجلات علمی
کلیدواژه‌ها	Goldfish, Reproduction, Seasonality, Sex Steroid, Eggs
چکیده	Mature female goldfish (Carassius auratus) stripped during the four consecutive seasons (spring, summer, autumn and winter) using simple environmental and hormonal treatments. Plasma levels of sex steroid profiles (17$-estradiol (E ), 17"-hydroxyprogesterone (17"OHP)), plasma calcium, gonadosomatic index (GSI) 2 as well as a range of indices of ovarian development and potential of eggs production during each season were evaluated. There were no significant differences between absolute fecundity and relative fecundity during the four stripping seasons (P>0.05). Mean oocyte diameter showed a significant increases during the second stripping seasons (summer; 1.32±0.10 mm; P<0.001). Significant higher levels percentage of hatching observed in the spring (96.0±1.82 %) compared with values obtained from other seasons (P<0.001). The maximum one-day embryo survival and five-day larval survival were observed in the summer (94.33±2.94 and 88.80±1.92 % respectively). The changes in E , 17"-OH, calcium and GSI were accompanied with the gonadal cycle in 2 goldfish. In the four stripping seasons, plasma E and calcium were elevated during vitellogenesis and 2 decreased steadily one month prior to the initiation of spawning period. The maximum levels of 17"-OH was observed one month before ovulation These findings may be used to available of fry and eggs in freshwater aquarium fish such as goldfish at multiple times of the year without adverse effects on the quality of the eggs and larvae.
پژوهشگران	اکبر بهارلویی (نفر چهارم)، علی شعبانی (نفر سوم)، محمد رضا ایمانپور (نفر دوم)، وحید زادمجید (نفر اول)