Todisco Vittoria, Fridolfsson Emil, Axén Charlotte, Dahlgren Elin, Ejsmond Maciej J, Hauber Marc M, Hindar Kjetil, Tibblin Petter, Zöttl Markus, Söderberg Linda, Hylander Samuel
Centre for Ecology and Evolution in Microbial Model Systems (EEMiS), Linnaeus University, Kalmar, Sweden.
Section for Fish, National Veterinary Institute (SVA), Uppsala, Sweden.
J Fish Biol. 2024 Mar;104(3):807-824. doi: 10.1111/jfb.15584. Epub 2023 Dec 7.
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.
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。在过去几十年中，全球多个鲑科物种都出现了因硫胺素缺乏导致的繁殖失败，但尚不清楚为何会出现这种微量营养素缺乏的情况。很少有研究比较过有或没有记录到硫胺素缺乏的鲑科种群系统中的硫胺素浓度。此外，对于硫胺素浓度在海洋摄食阶段和产卵洄游期间是否以及如何变化，人们也知之甚少。因此，在波罗的海开阔海域积极摄食时、洄游到出生河流后、河流洄游后以及产卵期间，采集了大西洋鲑（Salmo salar）的样本。为了将波罗的海鲑鱼种群与没有记录到硫胺素缺乏的系统进行比较，还对位于韦纳恩湖（瑞典）的陆封型鲑鱼种群以及流入北大西洋的挪威河流中的鲑鱼进行了采样。结果显示，韦纳恩湖鲑鱼的平均硫胺素浓度最高，其次是北大西洋的鲑鱼，波罗的海种群的浓度最低。因此，波罗的海的鲑鱼似乎比其他系统中的鲑鱼更容易受到硫胺素的限制。在所有系统中，状况因子和体长对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。在我们对鲑鱼种群进行的大规模时空比较中，所有研究系统中的硫胺素浓度在产卵时都会下降，这表明硫胺素浓度的降低是饥饿的自然结果，而不是与系统中的硫胺素缺乏有关。这些结果表明，影响海洋摄食阶段积累的因素是理解鲑科鱼类硫胺素缺乏的关键。
