Why do my fish seem to hide all the time ?

Why do my fish seem to hide all the time ?

Fish are creatures of instinct and naturally adaptive behaviour. Why are some fish shyer / bolder than others ? Some fish seem to hide all the time and I never get to see them. What can I do to get my fish more comfortable ? What types of fish are more inclined to be comfortable in my tank ?

CanadAquaria Members discuss the various behaviours of shy / bold fish, how various tank setups improve their comfort, and the fishes inclination to be visible and active.

There are several reasons I know of for excessive hiding.

The most common is that your fish have nowhere to hide. In a tank that is bare, undecorated or too bright, tiny fish like the ones we keep are terrified. The dangers they await are large predators and birds. They'll hover close to a hiding place and gain confidence in their surroundings, if they have a hiding place. Fish like a Plan B, even if they don't have to use it.

Many fish aren't really individuals, but part of a shoal. They live and survive in groups, and can't handle solo living. In their species, you are only alone if something has killed all of your companions. Can you blame them for hiding when we keep them alone? They don't know where the thing is that wiped out their species, but they know it has to be out there somewhere, probably behind your sofa.

Many shoaling fish release fear chemicals into the water when frightened. These are chemical warnings that spread with the current and disappear in nature - but not in fishtanks. A water change can help weaken that panic message.

Your fish could be a hardwater evolved species being kept in too soft water, or a fish needing pristine water living in polluted conditions. Water quality problems will cause hiding, and are often a first symptom of velvet disease (oodinium sp), a potentially fatal skin parasite.

There are two final, related reasons. Some species live by hiding. They have evolved in a habitat where fish their size have to stay under cover, and aquarium living won't change that. These fish tend to be ambush hunters, though their food can be very tiny.
Plus, they might really have a reason to be afraid. You could have put a predator or a violently territorial fish in your tank. Often, when fish breed, their behavior changes and all their tankmates run for cover. The parent fish want everyone out of the way to keep their babies off the menu, and they will kill to defend breeding space, eggs, larvae or fry.

Just because your fish have gotten along fine for a few months doesn't mean some of them won't change as their teenaged hormones kick in. Fish are never each others' friends. Intelligent ones will recognize individuals in their tank, and some species will pair for life - but most of the time they hang together for defence and breeding in a world of rank and pack type behavior. If something changes the balance of power in the tank, hiding can be the weaker individual's only hope.

I'm sure there are other reasons too. Cats, kids, vibrations from music, cats, flashing lights, tanks close to the floor, cats...

Well said Gary  

I know that it sounds funny, but I too have learned that, the more hiding places for fish, the more you see them!

Also, when we got our first four black skirt tetras, they often stayed close to the corners of the 10g, or under the one fake plant we had in there. Once we moved them into the 55g, and added many plants, they were out a little more, but weren't very active. We were amazed at how much more active they became once we added more skirts - now with 15 in the 55g, they rarely hide and generally move around together constantly! Being schooling fish, the key to seeing them active was both lots of friends and hiding spots!

wow! Gary you are so smart!!!!!
and folks Shell's 55 gallon is spectacular...truly!

Amazing answer Gary! I bet you are a great teacher

My Celestial pearl danios are in a heavily planted, broad tank with tons of hiding places, and I can never see all of them at once. I had 8 to start with and am not even 100% sure whether they're all still there or not. I wish i had gotten more while the pet store still had them... but now the store can't get them anymore for a semi reasonable price. in the same tank my habrosus cories (x8) are bold as brass.