Abstract:
The increasing use of alternative feeds for sustainable aquaculture leads to a reduced selenium content requiring the use of supplements to maintain the antioxidant status of farmed fish. The introduction of tuna by-products in fish feed is attractive for their selenium content, but the presence of mercury limits their use as it may negatively impact fish health. Indeed, selenium and mercury metabolism, in relation to their interaction and biological effects in fish, is far from being fully understood. This study aims to assess the impact of parental and dietary supplementation with selenomethionine and methylmercury on selenium and mercury localisation and concentrations in tissues of 3-week rainbow trout fry. Six diets were used. Broodstock were fed a plant-based diet Bpc (with 0.2 μg g-1 selenium and 0 μg g-1 mercury) or a tuna by-product-based diet Bt (with 4 μg g-1 selenium and basal mercury at 0.2 μg g-1) during 6 months, supplemented or not with 4 μg g-1 of selenomethionine for the plant-based diet Bpo and/or with 2 μg g-1 of methylmercury for diets Bph, Bpho and Bth. Their offspring were fed the plant-based diet Fpc, supplemented or not with the same levels of selenomethionine and methylmercury, until their third week. Mercury and selenium concentrations were determined in fry whole-body by ICP MS and quantitative images of selenium and mercury were produced by LA-ICP MS from fry whole-body thin sections. Dietary supplementation of fry with selenium and/or mercury increased their concentration in all tissues, especially in liver, kidney, muscle and intestine. Parental selenomethionine supplementation had a more pronounced effect on fry selenium levels than tuna by-products diet. Mercury transfer from broodstock to their offspring was weak. Mercury concentrations decreased in the kidney of fry supplemented with both selenium and mercury, which could be related to the presence of selenium.
摘要:
用于可持续水产养殖的替代饲料的越来越多的使用导致硒含量降低,需要使用补充剂来维持养殖鱼类的抗氧化状态。在鱼饲料中引入金枪鱼副产品对其硒含量具有吸引力,但是汞的存在限制了它们的使用,因为它可能会对鱼类健康产生负面影响。的确,硒和汞的代谢,关于它们在鱼类中的相互作用和生物效应,还远远没有被完全理解。这项研究旨在评估父母和饮食中硒代甲硫氨酸和甲基汞对3周虹鳟鱼鱼苗组织中硒和汞定位以及浓度的影响。使用了六种饮食。饲喂基于植物的饮食Bpc(含0.2μg。g-1硒和0μg。g-1汞)或基于金枪鱼副产品的饮食Bt(含4μg。g-1硒和0.2μg的基础汞。g-1)在6个月内,补充或不补充4μg。g-1的硒代蛋氨酸,用于植物性饮食Bpo和/或2μg。g-1的甲基汞的饮食Bph,Bpho和Bth.他们的后代被喂食植物性饮食Fpc,补充或不补充相同水平的硒代蛋氨酸和甲基汞,直到他们的第三周。通过ICPMS测定鱼苗全身中的汞和硒浓度,并通过LA-ICPMS从鱼苗全身薄片中产生硒和汞的定量图像。饮食中补充硒和/或汞会增加其在所有组织中的浓度,尤其是肝脏,肾,肌肉和肠道。与金枪鱼副产品饮食相比,父母补充硒代蛋氨酸对鱼苗硒水平的影响更为明显。汞从亲鱼到后代的转移很弱。补充硒和汞的鱼苗肾脏中的汞浓度降低,这可能与硒的存在有关。