Goldfish Behavior
Wouldn't it be amazing if you could get to know your goldfish better, learn more about its behavior and become best friends? Of course you want it! It's commonly that owners get to love their pets more and more once they learn more about them. Ok, lets begin.
First of all, it's normal to see your goldfish swim, play and explore during the day and sleep at night. Do fish sleep? Yes, but because they have no eyelids, they can't close their eyes like we do.
The goldfish behavior can be influenced by the environment, tank mates and also by its owner. As you spend your time every day at the aquarium or pond getting to know your fish, you might seem surprised to find out that your goldfish are learning more and more about you. It may also be surprising to know that research scientists recently conducted an experiment where goldfish succeeded in maneuvering a movable tank over land towards a visual target. Universities often receive research grants or conduct complex research and development experiments. Documenting the results of academic research involving goldfish may even qualify for an R&D tax credit under certain circumstances.
Everyone knows that every creature on this planet needs a friend. Don't hesitate to buy one pair of goldfish or even more if your budget allows you to get a bigger aquarium. Having a friend, your goldfish will be less exposed to stress, will have a partner to play with, nib at each other, pecking the gravel and talk about what's on the menu today.
Is it true that goldfish can recognize people when they swim up to the glass of the tank?
Yes, this is normal goldfish behavior and very common these days.
Goldfish are not as smart as other pets like cats or dogs, but they can easily tell that the people they live with love them. Usually goldfish swim up to meet you because they think you are going to feed them. They know they depend on you and love you back.
Goldfish love to...
- play all day and explore your aquarium (large spaces)
- eat tasty and healthy food (varied diet)
- have lots of friends
- take a nap once in a while (when they get tired)
- hide behind a plant or in a cave when they feel in danger
- mating during breeding season (get frisky when water becomes warm)
- eat from owners hand (when they get used to you)
Goldfish don't like to to...
- swim upside-down
- stay all day at the bottom of the aquarium
- live in an unhealthy environment
- live in small places like bowls or small tanks
- contact diseases
- eat only goldfish flakes every day
- have to swim at the top to get more oxygen
- get chased by other fish
- get touched by the owner
- have the lights turned On at night
- listen to loud music
- scratch itself against the sides
It's so simple, even a 6 year old can tell if their goldfish is happy and healthy by using the goldfish behavior like/hate tips.
Aggressive goldfish?
A goldfish personality can vary from fish to fish. I have owned timid goldfish as well as some very outgoing. Let me tell you this: goldfish are typically non aggressive to goldfish or any other fish, but as weird as it sounds they love to eat their own eggs if these are not removed from the aquarium.

You must know that during the mating season male goldfish tend to become a bit aggressive and "chase" the female.
Unfortunately goldfish tend to get aggressive with each other and start nipping at other fish when they are stressed.
This happens when they are not eating well, don't have enough room to move about and it rarely happens to pick on other sick fish.
As soon as you see goldfish become aggressive you need to separate them. However, you can overcome similar goldfish behavior problems if you follow the basic tips and how to's thought on this site and go trough the Goldfish Care Mini-Course. It's a simple and exact process to follow.
It's common for owners to start feeding their goldfish by hand once their pets get used to them. It's a fact that goldfish have memory that lasts up to 3 months. That means they can recognize different human voices and faces.
Q & A
Q: Two goldfish keep fighting in my 5 gallon aquarium. What should I do?
A: You simply can't add one goldfish in a 5 gallon tank, not even think about two.
You need at least 10 gallons of water per goldfish. A minimum 25 gallon tank will
keep your goldfish from fighting and also keep them happy.
Q: Why does my goldfish float upside down for hours after he eats?
A: Swim Bladder disorder is a very common problem and it occurs when owners overfeed
their goldfish. This happens when the fish becomes constipated and causes it to float
to the surface and hang there, like a helium balloon stuck on the ceiling. To overcome
this problem you need to starve your fish for two days or feed him few cooked peas(or beans)
also for 2 days.
To prevent this from happening in the future, you need to feed your fish what they can eat in 2 minutes, once a day. Also a varied diet consisting of fruit and veggies are highly recommended. Please visit Feeding Goldfish article for more info.
Q: Why is my goldfish changing color?
A: This is a normal situation. Some goldfish change their scale coloration from orange to black
or from black to orange as they age. Keep an eye on your goldfish, but don't worry at the moment.
However, if there are signs that their scales are pale and start to lose their brightness then you may have a problem. Sometimes it's because a disease or the poor fish is lacking vitamins. Feed veggies and fruit daily. Check out the Goldfish Diseases Article.
Q: Why is my goldfish gulping at the surface?
A: The problem here is with your water quality. Your goldfish is not getting enough oxygen.
Check your pump and make sure the water is not toxic. If you have a bowl or a small tank(under 10 gallons)
you need to upgrade and do 20-30% water changes every week or twice a week(for 2 weeks.)
Q: Why won't my new goldfish eat?
A: Goldfish are a bit stressed when being moved into a new tank. Give them a day or two, then try again.
Make sure you remove the uneaten food out of the tank so you don't get a build up in ammonia.
Q: Why did my goldfish stop eating?
A: Most goldfish problems stem from one thing: poor water quality. You need to do a 30% water
change and keep this up once a week. If things don't get better in 2-3 days, visit the Goldfish
Diseases page, check out for symptoms, see what you need to do to fight off the disease. Don't
forget about not to overfeed.
* This also applies for goldfish that are not moving from the bottom of the tank.
Love to you,
Flo
Useful Articles
Goldfish Babies | Learn How To Raise Them Healthy
Essential Goldfish Care Guidelines
Goldfish Tanks - Buying The Aquarium You Dream About
Feeding Goldfish The Healthy Way | Benefits and Tips
Goldfish Names - Fantastic Ideas For Your Pet
Image credits to: boringest @ Flickr.com