Research Unit in Environmental and Evolutionary Biology (URBE), Institute of Life, Earth & Environment, University of Namur (UNamur), 5000, Namur, Belgium.
Louvain Institute of Biomolecular Science and Technology, UCLouvain, Croix du Sud 4-5/L7.07.03, B-1348, Louvain-la-Neuve, Belgium.
Fish Physiol Biochem. 2021 Aug;47(4):979-997. doi: 10.1007/s10695-021-00959-0. Epub 2021 May 11.
In stocking program, the use of artificial incubation conditions in hatcheries from the fertilisation of eggs to the release of unfed fry could reduce their ability to adapt to the natural environment. This study evaluates the effects of three factors on the fitness and physiology of salmon fry at their emergence, the origin of water (river vs drilling), the type of support in the incubator (support matrix vs plastic sheets) and the type of incubators (Californian vs vertical trays), and compares them to a semi-natural incubation method in river. Key biological functions including nutritional and immune status were compared among experimental conditions using biometric parameters, lipid composition and gene expression analyses. Our findings demonstrated that fry incubated in vertical trays supplied with river water had no significant difference in growth and lipid composition compared to those in semi-natural incubators. Besides, fry incubated on a substrate matrix in Californian trays exhibited phenotypic characteristics closest to those incubated in river. This support matrix improved fish growth, lipid consumption and distribution compared to fry on plastic sheets. Moreover, the large amounts of several PUFAs in these fry could allow a better membrane fluidity ensuring a better adaptation to temperature variation under cold conditions. In addition, drilling water improved the survival rate compared to river water due to lower numbers of fine particles, known to be responsible for the clogging of eggs. To conclude, using a substrate combined with drilling water in artificial incubators could increase fry fitness and its adaption to wild life.
在 stocking 计划中，在孵化场中从受精到释放未喂食的鱼苗阶段使用人工孵化条件可能会降低它们适应自然环境的能力。本研究评估了三个因素对鲑鱼苗在孵化后的适应性和生理机能的影响，这三个因素分别是水的来源（河流与钻井）、孵化器中的支撑物类型（支撑基质与塑料片）以及孵化器的类型（加利福尼亚式与垂直托盘），并将其与河流中的半自然孵化方法进行了比较。使用生物计量参数、脂质组成和基因表达分析等方法比较了实验条件下的关键生物学功能，包括营养和免疫状态。我们的研究结果表明，与半自然孵化器相比，用河流水供应的垂直托盘孵化的鱼苗在生长和脂质组成方面没有显著差异。此外，在加利福尼亚式托盘上用基质支撑物孵化的鱼苗表现出的表型特征最接近在河流中孵化的鱼苗。与在塑料片上的鱼苗相比，这种基质支撑物提高了鱼苗的生长、脂质消耗和分布。此外，这些鱼苗中大量的多种多不饱和脂肪酸可以提高膜的流动性，确保在寒冷条件下更好地适应温度变化。此外，钻井水由于含有较少的细颗粒，提高了鱼苗的存活率，而这些细颗粒已知会导致卵堵塞。总之，在人工孵化器中使用基质和钻井水可以提高鱼苗的适应性和生存能力。
