Do my fish have nightvision?

B.T.W. They are goldfish

Most Goldfish have terrible eyesight. About one inch during the day. They use what is called their “lateral line” for navigation.

Lateral Line

But why are my goldfish not dead then?

The food causes enough of a disturbance that the fish can sense the food when it hits the water and when it falls through the water. They are really that sensitive to vibrations. That is why tapping on the glass is so bad for them.

Your answer is really appreciated, John. Thank you!

One more question, which involves that sense for vibrations.
When people (like visitors) talk very very loud (in the direction of the fish) can they sense the vibrations from the sound too?

And what about the hearing of fish. Is that bad as well?

They look like they’re scared then.

Yes, they can sense the vibrations.. I wouldn’t be concerned about it. Loud music with lots of bass has been known to kill some fish in tanks. Think fish tanks in nightclubs. A un-amplified human voice should not cause any damage.

I’m not really sure if they can hear like we do.. I doubt it.. They sense vibrations similar to how our eardrums do. How those are translated I don’t know..

Do you have fish?

Yeah, I have a tank that is a 15 gallon “high” with eight goldfish and six living plants. I love having it.. I can watch them for hours. I find it super relaxing. I got my first tank when I was about thirteen years old and I am 29 now. It was a good lesson about responsibility that I really needed at the time.

I tried having a saltwater tank and that didn’t work out so well.

I am 13 and I have a round tank with 2 fish. I really want an aquarium, but my parents don’t let me. If I may buy a aquarium, I put everything in it what makes a fish happy. I love them, and I want them to grow old, but others don’t respect that…

A little piece of advice.. Be really careful with how much food you give them. It is much better to underfeed them. Uneaten food can really boost the nitrite levels in such a small tank. That is really bad for the fish. It would take weeks for your fish to die if you stopped feeding them. Giving them a little less won’t hurt them.

If you get a tank with under the gravel filtration it doesn’t matter as much. Without water being filtered through the rocks it makes it easier for uneaten food to become toxic.

And I respect the fact that you want your fish to grow old and be happy.

I once put some goldfish in a turtle tank, and the next day half the goldfish were gone (oops). So I guess that turtles have better night vision than goldfish.