Zhang Pian, Tan Peng, Zhang Lei, Zhu Wenliang, Chen Ruiyi, Wang Ligai, Xu Dongdong
Fisheries College, Zhejiang Ocean University, Zhoushan 316022, China.
Key Laboratory of Mariculture and Enhancement, Zhejiang Marine Fisheries Research Institute, Zhoushan 316021, China.
Aquac Nutr. 2023 Mar 16;2023:5545898. doi: 10.1155/2023/5545898. eCollection 2023.
This study is aimed at establishing optimal soybean lecithin (SL) enrichment protocols in nauplii and at comparing the growth performance, body composition, and liver tissue metabolism in rock bream () larvae reared on SL-enriched nauplii or SL-enriched microdiet (MD). The enrichment protocol experiment results indicated 12 h enrichment, and 10 g SL/m seawater could obtain desirable results. Rock bream larvae (25 days posthatching (dph)) were fed nauplii or MD for 30 days with three replicates. At stage 1 (larval 25-40 dph), significantly higher growth performance was observed in larvae fed the live prey ( < 0.05). Conversely, at stage 2 (41-55 dph), feeding with MD significantly increased larval standard length, and specific growth rate compared with those of larvae fed live prey. Larvae fed a MD showed decreased lipolysis-related lipase activity as well as decreased amino acid catabolism-related alanine aminotransferase and aspartate aminotransferase enzyme activities in liver tissue. RNA sequencing revealed that feeding with the MD primarily increased the expression of lipogenesis-related genes and protein translation-related gene expression in the liver tissue. Notably, feeding with MD significantly increased ribosome biogenesis-related genes as well as mitochondria synthesis-related gene expression, indicating a high protein anabolism rate and high energy production in liver tissue. In conclusion, 10 g SL/m seawater and 12 h could effectively enrich SL in nauplii. Retard weaning onto MD led to lower growth performance, which was likely due to the diversity of lipid and protein metabolism.
本研究旨在建立无节幼体中大豆卵磷脂（SL）的最佳富集方案，并比较用富含SL的无节幼体或富含SL的微颗粒饲料（MD）饲养的条石鲷（）幼鱼的生长性能、体成分和肝组织代谢。富集方案实验结果表明，12小时的富集时间和每立方米海水中10克SL可获得理想结果。将条石鲷幼鱼（孵化后25天（dph））用无节幼体或MD喂养30天，每组设三个重复。在第1阶段（幼体25 - 40 dph），喂食活饵的幼鱼生长性能显著更高（<0.05）。相反，在第2阶段（41 - 55 dph），与喂食活饵的幼鱼相比，用MD喂养显著增加了幼鱼的标准体长和特定生长率。喂食MD的幼鱼肝脏组织中与脂肪分解相关的脂肪酶活性以及与氨基酸分解代谢相关的丙氨酸转氨酶和天冬氨酸转氨酶活性均降低。RNA测序显示，用MD喂养主要增加了肝脏组织中与脂肪生成相关基因的表达以及与蛋白质翻译相关基因的表达。值得注意的是，用MD喂养显著增加了与核糖体生物合成相关的基因以及与线粒体合成相关的基因表达，表明肝脏组织中蛋白质合成代谢率高且能量产生高。总之，每立方米海水中10克SL和12小时可有效富集无节幼体中的SL。延迟断奶改用MD会导致生长性能降低，这可能是由于脂质和蛋白质代谢的差异所致。
