Goldfish
The goldfish ("Carassius auratus") is a freshwater fish in the family Cyprinidae of order Cypriniformes. It is one of the most commonly kept aquarium fish.
Common goldfish
The sun is important to introduce to the goldfish frequently; due to the fish living in well-lit conditions in the normal wild environment, it is necessary to keep a similar environment for the fish. The light will also help the goldfish with its sleeping cycle, giving the goldfish a healthy sleeping schedule to stay healthy. The goldfish should not be kept all day in the hot sun, as this could possibly kill the fish and make the environment hostile. A tank light is available as an alternative but not necessary.