Author(s): Zou, YX (Zou, Yuxia); Peng, ZZ (Peng, Zhuangzhuang); Wang, WX (Wang, Wenxiang); Liang, SS (Liang, Shaoshuai); Song, CB (Song, Changbin); Wang, LJ (Wang, Lijuan); Wu, ZH (Wu, Zhihao); Wu, QW (Wu, Qiaowan); Tan, XG (Tan, Xungang); You, F (You, Feng)

Source: AQUACULTURE Volume: 546 Article Number: 737275 DOI: 10.1016/j.aquaculture.2021.737275 Published: JAN 15 2022

Abstract: The light spectrum is one of the photic environmental factors. To investigate the effects of the light spectrum on the growth, testicular development and stress in fish, the olive flounder (Paralichthys olivaceus) from total length 1.5 cm were exposed to green light or white light for 205 days. The total length and body weight of the flounder reared under green light were significantly higher than those under white light. No significant difference in survival rate was found between the two groups. Levels of growth hormone (GH) and insulin-like growth factor (IGF) in serum were higher in flounders exposed to green light than those to white light. The gene expression levels were analyzed by quantitative-real time PCR. In hypothalamus, the mRNA levels of salmon gonadotropin-releasing hormone 3 (gnrh3) were significantly higher in the flounders exposed to green light than white light (p < 0.01); while melatonin receptor 1 and melatonin receptor 2 mRNA level was significantly lower in the green group (p < 0.05). In pituitary, luteinizing hormone (beta-subunit mRNA level was significantly higher under green light (p < 0.05). Gonadal histology analysis showed that there was significant difference in the testicular development between the two groups. Cortisol level was higher in flounders exposed to green light than white light both in the whole body and in serum. In conclusion, green light could promote growth by elevating GH and IGF levels in serum and expression levels of gnrh3 in hypothalamus, stimulate testicular development via hypothalamus-pituitary-gonad axis, and cause higher levels of cortisol in flounder. These results indicate green light could be used in aquaculture to increase production and be helpful for breeding.

Accession Number: WOS:000729132800009

ISSN: 0044-8486

eISSN: 1873-5622

Full Text: https://www.sciencedirect.com/science/article/pii/S0044848621009388?via%3Dihub