Abstract：
Thiamin is an essential water-soluble B vitamin known for its wide range of metabolic functions and antioxidant properties. Over the past decades, reproductive failures induced by thiamin deficiency have been observed in several salmonid species worldwide, but it is unclear why this micronutrient deficiency arises. Few studies have compared thiamin concentrations in systems of salmonid populations with or without documented thiamin deficiency. Moreover, it is not well known whether and how thiamin concentration changes during the marine feeding phase and the spawning migration. Therefore, samples of Atlantic salmon (Salmo salar) were collected when actively feeding in the open Baltic Sea, after the sea migration to natal rivers, after river migration, and during the spawning period. To compare populations of Baltic salmon with systems without documented thiamin deficiency, a population of landlocked salmon located in Lake Vänern (Sweden) was sampled as well as salmon from Norwegian rivers draining into the North Atlantic Ocean. Results showed the highest mean thiamin concentrations in Lake Vänern salmon, followed by North Atlantic, and the lowest in Baltic populations. Therefore, salmon in the Baltic Sea seem to be consistently more constrained by thiamin than those in other systems. Condition factor and body length had little to no effect on thiamin concentrations in all systems, suggesting that there is no relation between the body condition of salmon and thiamin deficiency. In our large spatiotemporal comparison of salmon populations, thiamin concentrations declined toward spawning in all studied systems, suggesting that the reduction in thiamin concentration arises as a natural consequence of starvation rather than to be related to thiamin deficiency in the system. These results suggest that factors affecting accumulation during the marine feeding phase are key for understanding the thiamin deficiency in salmonids.
摘要：
硫胺素是一种必需的水溶性B族维生素，以其广泛的代谢功能和抗氧化特性而闻名。在过去的几十年里，在世界范围内的几种鲑鱼物种中观察到硫胺素缺乏引起的生殖衰竭，但目前还不清楚这种微量营养素缺乏的原因。很少有研究比较有或没有记载的硫胺素缺乏的鲑鱼种群系统中的硫胺素浓度。此外，目前尚不清楚硫胺素浓度在海洋取食阶段和产卵迁移过程中是否以及如何变化。因此,大西洋鲑鱼（Salmosalar）的样本是在波罗的海海域积极摄食时收集的，在海洋迁移到出生河流之后，河流迁徙后，在产卵期。为了比较波罗的海鲑鱼的种群与没有记录的硫胺素缺乏的系统，对位于Vänern湖（瑞典）的内陆鲑鱼种群以及从挪威河流排入北大西洋的鲑鱼进行了采样。结果显示Vänern湖鲑鱼的平均硫胺素浓度最高，其次是北大西洋,也是波罗的海人口中最低的。因此，波罗的海的鲑鱼似乎比其他系统的鲑鱼始终受到硫胺素的约束。条件因子和体长对所有系统中的硫胺素浓度几乎没有影响，这表明鲑鱼的身体状况与硫胺素缺乏之间没有关系。在我们对鲑鱼种群的大规模时空比较中，在所有研究的系统中，硫胺素浓度向产卵方向下降，这表明硫胺素浓度的降低是饥饿的自然结果，而不是与系统中硫胺素缺乏有关。这些结果表明，影响海洋摄食阶段积累的因素是了解鲑鱼中硫胺素缺乏的关键。本文受版权保护。保留所有权利。
