The video shows a large eel swimming in a tank with other fish. The eel is dark green in color and has a long, slender body. The other fish are smaller and have different colors. The tank is blue and has a glass wall. The eel moves slowly through the water, occasionally turning its body. The other fish swim around the eel, sometimes coming close to it. The lighting in the tank is bright, illuminating the eel and the other fish.