PDF(Pubmed)
Abstract：
The feeding rhythm is one of the key factors determining the success of artificial breeding of S. paramamosain. To understand the feeding rhythm of the different zoea larva developmental stages of S. paramamosain, the feeding rate, digestive enzyme activity, and expression of metabolism-related genes were investigated in the present study. The results showed that the S. paramamosain feeding rate has strong diurnal feeding rhythm, being significantly higher at 10:00-14:00 from stages ZI to ZIV. While the feeding rate peaked at 14:00 on Days 10 and 11, the peak shifted to 18:00 on Day 12. The activity of digestive enzymes amylase, pepsin and lipase decreased at night but increased in the daytime, showing a single-phase rhythm similar to that of the feeding rate, suggesting that the digestive enzyme activity was closely associated with the feeding rate during the larval development. Compared to pepsin and lipase, the activity of amylase was the most consistent with feeding rate. In particular, amylase activity peaked at 18:00 on Day 12. Due to its synchronicity with feeding activity, the activity of amylase could provide a potential reference for determining the best feeding time during zoea stages in S. paramamosain breeding. Moreover, the relative mRNA expression of metabolism-related genes SpCHH and SpFAS at most tested points was lower from 10:00 to 14:00, but higher at 18:00 to 6:00 of the next day. On the other hand, the expression patterns of SpHSL and SpTryp were converse to those of SpCHH and SpFAS. Our findings revealed that the S. paramamosain zoea has an obvious feeding rhythm, and the most suitable feeding time was 10:00-18:00 depending on different stages. The feeding rhythm is a critical aspect in aquaculture, influencing a series of physiological functions in aquatic animals. This study provides insights into the feeding rhythm during the zoea development of S. paramamosain, making a significant contribution to optimizing feeding strategy, improving aquafeed utilization, and reducing the impact of residual feed on water environment.
摘要：
摄食节奏是决定紫草素人工繁殖成功的关键因素之一。为了解paramamosain幼虫不同发育阶段的摄食节奏，喂食率，消化酶活性，并对代谢相关基因的表达进行了研究。结果表明，紫草素的摄食率具有较强的昼夜摄食节律，从ZI到ZIV阶段，在10:00-14:00明显更高。虽然喂食率在第10天和第11天的14:00达到峰值，但峰值在第12天移至18:00。消化酶淀粉酶的活性，胃蛋白酶和脂肪酶在夜间减少，但在白天增加，显示出类似于喂食速率的单相节律，表明在幼虫发育过程中消化酶活性与摄食率密切相关。与胃蛋白酶和脂肪酶相比，淀粉酶的活性与摄食率最一致。特别是,淀粉酶活性在第12天的18:00达到峰值。由于其与摄食活动的同步性，淀粉酶的活性可以为S.paramamosain育种中zoea阶段最佳摄食时间的确定提供潜在的参考。此外，在大多数测试点，代谢相关基因SpCHH和SpFAS的相对mRNA表达在10:00至14:00较低，但在第二天的18:00至6:00较高。另一方面,SpHSL和SpTryp的表达模式与SpCHH和SpFAS的表达模式相反。我们的发现揭示了S.paramamosainzoea具有明显的摄食节律，根据不同阶段，最合适的喂养时间为10:00-18:00。摄食节奏是水产养殖的一个关键方面，影响水生动物的一系列生理功能。这项研究提供了对S.paramamosain的zoea发育过程中的摄食节奏的见解，为优化喂养策略做出了重大贡献，提高水产饲料利用率，减少了饲料残留对水环境的影响。
