Histopathological effects of different selenium and iron nanoparticle levels on the intestine of beluga (Huso huso) juvenile

Selenium is an essential trace element for animals, including fish, and it is considered as an excellent essential nutrient for increasing production in aquaculture. Iron is one of the microelements that has a significant effect on the natural activities of fish organs and is an essential element for many metabolic processes such as oxygen transport, drug metabolism, steroid synthesis, DNA synthesis, ATP production, and electron transfer. With the introduction of nanotechnology into the field of aquaculture, its practical use has expanded in many countries. So, this study aimed to investigate the effect of different levels of selenium nanoparticles (Se-NPs) and iron nanoparticles (Fe-NPs) levels on the histopathology of the intestine of the beluga juvenile. ۱۳۵ beluga juvenile (with initial weight of ۲۷۶.۴±۳۲.۳ g and initial length of ۴۰.۰±۲.۰ cm) were randomly distributed in ۲۷ fiberglass tanks at ۹ different treatments with ۳ replicates. Treatments including T۱ (control, no added NPs), T۲ (۱ mg/kg Se-NPs), T۳ (۲ mg/kg Se-NPs), T۴ (۱۰۰ mg/kg Fe-NPs); T۵ (۱۰۰ mg/kg Fe-NPs +۱ mg/kg Se-NPs); T۶ (۱۰۰ mg/kg Fe-NPs +۲ mg/kg Se-NPs); T۷ (۲۰۰ mg/kg Fe-NPs); T۸ (۲۰۰ mg/kg Fe-NPs +۱ mg/kg Se-NPs); T۹ (۲۰۰ mg/kg Fe-NPs +۲ mg/kg Se-NPs). In order to find the histopathological changes, six fish tissues from each group (two fish of each replicate) were sampled at the end of the experiment. Tissues sample were fixed by immersing in Bouin’s fluid for ۲۴ h, then were dehydrated through ethanol series, cleaned with xyline and embedded in paraffin. Samples were serially sectioned using a Leitz microtome and mounted on glass slides. Sections were dried for ۲۴ h then stained with haematoxylin and eosin (H&E). Shortening of intestinal villi, fusion of the villi, vacuolation, necrosis of the villi were the most obvious signs in the intestine of the examined fish.

Keywords:

Nanoparticle , Selenium , Iron , Histopathology , Intestine , Villi , Fusion