Are Fish Able to See in the Dark?

Every now and then, images of creatures that live in the depths of the ocean are posted on social networks, and they tend to elicit gasps from those who see them for the first time. This has been happening more in recent years because of advances in underwater digital photography, and the species we’re seeing for the first time often have a terrifying appearance, at least when compared to the nice, friendly, and colorful fish we enjoy seeing in aquariums. To make matters worse, we give these creatures scary names to match their looks, such as pelican eel, goblin shark, dragonfish.

Something that’s even more interesting than the appearance of these species is their evolutionary traits. Marine biologists now know about fish—such as the silver spinyfin, which swims at depths of 2,000 meters—that can see in full color despite the relative lack of light. The vision of this particular fish is so evolved that it can capture even the most elusive photons. The aquarium experts at Aquatic Warehouse would like to share some details regarding the night vision abilities of other more familiar fish.

Goldfish

It might be tempting to think goldfish can see in the dark. After all, they’re extremely resilient and able to adapt to various habitats, but night vision isn’t one of their traits. Goldfish actually enjoy ecosystems that get plenty of light, preferably in the daytime. They can adapt to various sleep cycles, but they do need a few hours of darkness so they can retreat to a comfortable spot and relax.

Bettas

These colorful favorites of aquarium keepers can be moody and aggressive under some circumstances, but they cannot see in the dark. Like goldfish, they can adjust to periods of light and darkness, but they also enjoy resting when the lights go down.

Zebrafish

According to research published in the journal Communicative and Integrative Biology, zebrafish have advanced photoreceptors that would give them night vision abilities, but for some reason they choose to turn them off at night. In fact, they use their whiskers a lot more to swim and get around in the dark.

Cory Catfish

Cory catfish are ideal species for a fish tank because they get along reasonably well with other fish that are similar in size and they keep plants and sections of the bottom clean. River catfish are very active at night, which is when anglers set out to catch them, so they have enough night vision to feed in the darkness. Cories use all their senses to swim when there’s no light.

Blind Cavefish

Blind cavefish are blind from birth but have evolved with extremely accurate sensors that tell them exactly where objects are and what type of friend or foe is nearby.

Giving Aquarium Fish a Period of Darkness

Aquarium lamps help keepers admire their fish and determine the cleanliness and efficiency of the habitat, but these accessories also help fish regulate their active and rest cycles. Some species do well in the dark better than others, but all of them enjoy resting in darkness, which is a good reason to install a timer along with the aquarium lights.

Lighting is an important aspect of caring for fish in an aquarium, and you can find the highest quality LED lighting at Aquatic Warehouse, in addition to other essential supplies such as aquarium controllers, filtration, heaters, and more. Check out what we have to offer on our website, stop by our store in Kearny Mesa, or give us a call at 858-467-9297 if you have any questions.