Publications by authors named "Claudia Marchan-Moreno"

Tuna by-products in aquafeed pose challenges due to heavy metals like mercury (Hg), which has pro-oxidant effects. However, they also contain selenium (Se), an antioxidant oligoelement. This study assessed the oxidative impact of these elements in juvenile rainbow trout over a 6-month feeding trial.

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Article Synopsis
  • This study is the first to report selenium (Se) isotopes in marine top predators, specifically focusing on giant petrels, and provides extensive characterization of Se isotopes in animals.
  • A new methodology was developed using hydride generation and mass spectrometry to analyze various internal organs of the seabirds, revealing different Se isotopic signatures among tissues.
  • The findings show that the liver has higher concentrations of heavier Se isotopes and indicate a strong correlation between the presence of selenoneine and shifts in Se isotopic composition, suggesting a promising avenue for further understanding Se dynamics in animals.
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Article Synopsis
  • This study investigates how different forms of selenium (Se) affect mercury (Hg) accumulation in rainbow trout (Oncorhynchus mykiss) during a 6-month feeding trial.
  • The research tested twelve dietary conditions, including both plant-based diets and tuna byproduct diets, finding that the tuna byproduct diet led to lower Hg levels in fish compared to the plant-based options.
  • The results suggest that using specific Se compounds from tuna-based aquafeed can significantly reduce Hg bioaccumulation, promoting the use of fisheries byproducts in sustainable fish feeds.
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Birds are principally exposed to selenium (Se) through their diet. In long-lived and top predator seabirds, such as the giant petrel, extremely high concentrations of Se are found. Selenium speciation in biota has aroused great interest in recent years; however, there is a lack of information about the chemical form of Se in (sea)birds.

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Tiemannite (HgSe) is considered the end-product of methylmercury (MeHg) demethylation in vertebrates. The biomineralization of HgSe nanoparticles (NPs) is understood to be an efficient MeHg detoxification mechanism; however, the process has not yet been fully elucidated. In order to contribute to the understanding of complex Hg metabolism and HgSe NPs formation, the Hg isotopic signatures of 40 samples of 11 giant petrels were measured.

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