Can Goldfish See In The Dark? All Facts You Should Know

Can Goldfish See In The Dark? All Facts You Should Know

Despite having excellent eyesight, goldfish cannot see in the dark and must instead rely on their extraordinary sense of smell to find food. The lateral line organ in goldfish also aids in the detection of any vibrations and movements in the water, enabling them to spot their prey or predators in the dark.

Your goldfish may suffer serious health problems if you keep it in the dark all the time. Goldfish won’t be able to survive without light for very long because it can cause them to lose their natural colors and experience extreme stress, both of which can result in their death.

Goldfish require both a light and a dark phase; without both, they will grow stressed to the point that they become ill and may even perish. This means that while goldfish cannot survive in complete darkness, they can also not endure prolonged exposure to light.

Can goldfish eat in the dark?

Yes, goldfish can eat in the dark because they have an excellent sense of smell that guides them to food. However, they won’t be able to effectively consume food, hence the majority will go uneaten. Therefore, I recommend you feed your fish throughout the day or while your aquarium light is on.

Do goldfish need light at night?

It would be a good idea to incorporate light in your aquarium if your tank is in a dark place or if you wish to cultivate live plants, like hornwort. Remember to turn off the aquarium light at night to mimic the natural cycle of day and night.
Your goldfish will establish and maintain a healthy rhythm where it eats during the day and sleeps at night if you add an aquarium light and set a timer to govern regular intervals of “daylight” and “nighttime.” Even though they can readily swim through the night, goldfish do need time to rest.
Goldfish need darkness to sleep, just like humans. Goldfish do not lie down to sleep as people do. Instead, they slow down, remain stationary, and move gently to maintain stability. They often float close to the bottom of the tank or pond, about an inch above it, with their heads tipped slightly downward.

How do goldfish see underwater in the dark?

Deep-sea fish are able to move through complete darkness. The lateral line is a row of pressure-sensitive organs that runs along each side of a fish’s body, allowing fish to sense adjacent species by detecting changes in water pressure without actually seeing them.

Can your goldfish see outside the tank?

Yes, goldfish can see outside of their tank. They can scan the entire room for activity because of their excellent eyesight. Their vision will be worse as they move farther away or if dark which will result in decreased clarity in their vision.


Your goldfish use their keen sense of smell to find their way about in the dark because they are unable to see. Goldfish won’t be able to endure for very long in complete darkness. The aquarium lights should be turned off at night because goldfish require a healthy contrast between day and night. If you put your goldfish in total darkness, or in permanent light they will become stressed out, lose their color, and become ill.

You may be asking if other fish can see in the dark. I wrote another post that answers this question here.