Nano-Se and Fish: A Chorion Defense Tale

Have you ever thought about how tiny, man-made particles could affect fish? Well, let's dive into some interesting findings about selenium nanoparticles, or nano-Se. These tiny particles are big in the healthcare and farming worlds, but what about their impact on fish? Scientists decided to find out using Japanese medaka embryos. They exposed these little guys to different amounts of nano-Se, ranging from 0. 1 to 400 µM. The chorion, a protective shell around the embryos, was their first line of defense. But how well does it protect them?To answer this, researchers played with the chorion's condition in four ways: intact, roughened, partially dechorionated, and fully dechorionated. They also looked at the impact of particle size by using nano-Se particles of 16, 25-50, 50, and 100 nm. The results? Nano-Se exposure reduced survival, development, and hatching rates. Nano-Se was seen sticking to the chorion, with less sticking to more damaged chorions. The damage level influenced how toxic nano-Se was. Smaller particles were more dangerous, crossing intact chorions more easily. Interestingly, in larvae, nano-Se gathered on the skin and was more toxic than in embryos. This study shows just how crucial the chorion is in safeguarding developing embryos and how particle size matters in toxicity.