The video shows a fish swimming in an aquarium. The fish is dark in color and has a yellow spot on its side. It is swimming near the bottom of the tank, where there is a green plant. The fish seems to be exploring the area, moving its fins and tail to navigate through the water. The aquarium appears to be well-maintained, with clear water and a clean substrate. The fish's movements are smooth and graceful, and it seems to be comfortable in its environment.