1. Gender differences in response to 17β-estradiol in zebrafish (Danio rerio): Growth, physiology, and reproduction
- Author
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Hamed Abdollahpour, Naghmeh Jafari Pastaki, and Bahram Falahatkar
- Subjects
Estrogen ,Oral administration ,Zebrafish ,Growth performance ,Reproduction ,Ornamental fish ,Aquaculture. Fisheries. Angling ,SH1-691 - Abstract
The aim of this study was to find the effects of oral administration of 17β-estradiol (E2) on growth performance, gonadal development, and spawning performance in zebrafish (Danio rerio). For this purpose, fish (57 dph) were fed for 28 days with three treatments, including: 1) 0 mg E2 kg diet−1 (E0); 2) a low dose of E2 (1 mg E2 kg diet−1, E1); and 3) a high dose of E2 (10 mg E2 kg diet−1, E10). The growth in males and females in the E1 group was significantly higher than the other groups (P < 0.05). Higher and lower feed conversion ratios were found in the E10 and E1 groups, respectively (P < 0.05). Higher oocyte diameters were achieved in the E1 (448.6 ± 57.4 µm) and E10 (404.2 ± 47.5 µm) groups compared with the E0 group (238.9 ± 38.2 µm) (P < 0.05). Histological observations of the gonads indicated that testis in E1 group was more developed compared to the E10 and E0 groups. Moreover, most oocytes in E1 were in the final maturation stage (P < 0.05). Higher and lower hatching rates occurred in the E1 and E10 treatments, respectively (P < 0.05). Additionally, a higher mean number of larvae per brooders and higher mortality rates occurred in the E1 and E10 treatments, respectively (P < 0.05). According to the findings of this study, low doses of E2 improved spawning performance (higher hatching rate) and decreased larval mortalities, while at a high dose, it reduced reproductive performance in zebrafish. Overall, these results proposed 1 mg of E2 kg diet−1 is an effective dose for both male and female zebrafish growth, gonadal development and spawning performance.
- Published
- 2024
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