valuable commercial sterlet fish in the aquarium. a large single sturgeon fish swims behind glass in the exposition aquarium

acipenser acipenseriformes actinopterygii animal aquaculture aquarium background behind bottom caspian closeup commercial complex copy dnipro dnu eurasia exotic exposition fauna fish floating freshwater glass green large national natural nature one pebble river ruthenus single space sterlet sturgeon swim tank tropical ukraine underwater university valuable view wallpaper water wild wildlife zoo