A large group of fish swim in a deep blue aquarium

A large group of fish swim in a deep blue aquarium. The fish are mostly dark gray, with some lighter grey and white markings. There is a light sand colored bottom to the aquarium. The aquarium is located in Moskva, Russia (latitude: 55.833, longitude: 37.619). The fish are swimming in different directions, some are facing the camera and some are facing away. There is a shadow on the bottom of the tank from the light shining on the surface of the water. There are no people or other objects in the image.