Yes, goldfish do indeed see colors. Not just a few primary shades like most people think, but they see in four colors. Whereas humans only see in three main primary colors; red, green, and yellow! It makes goldfish tetrachromate. A goldfish hunts primarily by using its vision and senses, and only able to see within 15 feet in front of them. That means it needs to see a range of colors to detect food sources, navigate its way around the aquarium and choose ideal hiding spots where it can blend in.
We hope to explain a few concepts of how goldfish’s eyes see colors, and what colors are visible to our goldfish.
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How goldfish see colors
Goldfish can see color and detect objects in their surroundings by looking at how objects absorb, reflect, or translate colors. For goldfish to see in color, they have a retina at the back of their eye that contains color detectors. Goldfish have cones that allow them to see in color according to a specific combination of primary colors.
The colors goldfish can detect
Human eyes can see shades of red, blue, and yellow. Unlike humans, goldfish can see ultra-violet and infra-red lights, which makes them sensitive to polarized lighting occurring at dusk or dawn. Goldfish see the reflected light off the scales of neighboring fish, it helps them to detect each other and spot potential prey or predators, and avoid unwanted reflections under the water.
With such complex vision, goldfish can see a combination of red, green, blue, and ultraviolet light.
The importance of darkness
Goldfish do not have eyelids. This means they cannot close their eyes and sleep. Goldfish require 8 to 12 hours of total darkness. Setting a light period schedule for manual lighting and a timer for automatic lights ensures your goldfish get a light and dark cycle. When the light starts to diminish, goldfish start to see luminance, just like humans.
Once the environment falls dark, the goldfish will start to cease activity, and this is how they rest. You will notice their eyes will dart around and stare at you, this is normal and helps them keep an eye out for predators. Pond goldfish getting natural light and dark cycle have better eyesight than goldfish exposed to artificial light for longer periods. Although their eyesight is poor in darkness, they use their lateral line and smell to understand what is happening in the aquarium while they rest.
Do goldfish see color outside of the tank?
Yes! Goldfish can see outside of their tank and pick up different colors. If you are wearing a red top, your goldfish can see it. Although the glass distorts the colors and shapes beyond the aquarium walls. The glass can make the colors seem dull if the tank water has tannins or algae diatoms in the water column.
We hope this article has helped answer your questions! Many people do not know goldfish can see in color, let alone see more colors than we can. To make it easier on your goldfish’s eyes, try to keep artificial lights on a dim setting and make sure you do not have any moonlight replicating lights on at night. Goldfish are magnificent, along with their amazing colors and personalities, you now know they see in color, too!
Featured image credit: imsogabriel, Pixabay