Agressive goldfish ?

Question

Help! 2 of my goldfish (commons) and seriously gettin aggresive towards one of my smaller fish (fantail) .... theyve been living together for quite a while now in an 80 litre tank and only suddenly last night and this morning have the two commons been chasing the fantail very very fast and nipping the the side of its body and belly. They keep almost pushing it so close to the surface theres splashing. The fantail has been cornered several times in just half and hour.

Are they trying to kill it?

i have 2 other fan tails in the tank too- so why just this one?

help! i dont want my goldfish going belly up!

Answer 1

hi, this a common problem, pet stores if run by responsible people would advise you not to keep fancy types of goldfish with the traditional shape goldfish as fancy goldfish are more delicate.The problem you have is the common goldfish see the fancy fish as a swollen female with eggs inside her this has triggered spawning behaviour. the fancy fish wether male or female will get stressed quickly so it is best to seperate them. the way to stop this from happening again is to only keep either fancy or common goldfish together in the future.Try explaining the problem to the place where you bought them from and maybe swap them so you have all the same types of fish, this should not be a problem as you have been given the wrong advice. I hope this will solve your problem.

Answer 2

I'd suggest they were practising for breeding. If the fantail has a big belly the other two may assume it is carrying eggs. If they chase the fish too much it could die of exhaustion. Try to cool the water, that might help.
P.S. Don't mix common goldfish with round bodied goldfish, for this very reason!! Oh and yes, too many fish in a small space! They're not like birds that can be let out of the cage everyday, they spend their entire lives in the tank so make it a BIG one.

Answer 3

Single tailed goldfish (like commons) and fancy goldfish should never be mixed, having them all in only 21 gallons isn't helping either. Each single tailed goldfish needs 20 gallons just to itself when it is still a baby and 50+ when adults, they can grow 12-18 inches. Fancy goldfish need 10 gallons each when babies and 20+ when adults and can grow 8-12 inches. It could be they are cramped but it sounds more like breeding behavior, which is rough enough even when they are all fancies and they are slow swimmers. Your other fish may not kill the fish but it could stress it and cause damage which can become infected and can lead to other problems. The reason they are only chasing the one could be it is either the only female or the only female that is ready to breed. I suggest moving your commons out to a pond where they belong or give them away and get a bigger tank for your remaining 3 fantails.

Answer 4

The fish could have taken something that the other ones want. Ex. Commons wanted the last piece of food, but yet the fantial snapped it up!

Just like humans, when we want something and don't get it, we either get sad, angry, or agressive, in your case. To stop this fish-fighting, do the following:

Take a plastic baggie and a fish net and scoop out the fish that is getting attacked. Put it in the plastic baggie until you can do the next step. Do you have another fish tank? If not, you could just put it in some kind of glass jar or bowl. Make sure it will not fall over or spill somewhere!

Gently put the fantail fish into the glass jar or whatever you choose. Feed it daily or whatnot. Leave the fish alone seperately in that glass tank or whatever you put it in for about a week, so that the Commons fish can get used to it being gone, and give it some cooling off time.

I really do hope this solves your problem!

-Emily-

Answer 5

goldfish are not agressive, your fish are trying to spawn
the 2 commons must be your males and the fantail is the female,
make sure you have PLENTY of plants in your tank and some hiding places for the female, they can wear her out by chasing her so much
maybe you'll have some babies soon

Answer 6

You have way too many fish for that small space. The fantail will be lucky if it dies. Get the commons a seperate tank or pond.

Answer 7

Well I don't think it has anything to do with personal vendetta's! Fish have about a 3 second memory span, they forget things almost as soon as they've learnt them - Recent research has said they have about a three month span but looking at my own fish I doubt this is true!

I would separate the fish for a while though, perhaps just the one's who are being aggressive and hopefully they will learn unaggressive behaviour by the time you reunite them. Also, if the fantail IS pregnant, it would be best to separate her as her young will be eaten in the tank!

Answer 8

that is needed that you seperate them!!! A goldfish of mine quite died from mistreatment from a fellow fish. there is not any actual thanks to resign Pebbles from hurting Bubbles, so the most authentic way is to easily not grant a way that both can get at one yet another. in the journey that your field that they are in is decrease than 5 gallons, that should be the case; Pebbles is feeling territorial over the little area presented, and is proving his frustration on Bubbles. Get a higher tank in the journey that your cutting-edge one isn't 5 or better gallons, and if that doesn't artwork, you'll purely ought to seperate them. solid success!

Answer 9

,could be a female, when their spawning in a pond you can have lots of male chasing female they almost lift fish out off water,

Answer 10

your fantail could be pregnant and the goldfish are guarding their teritory of your fantail could have Kankor its a type of fish cancer the goldfish can sence this, goldfish can sence cancer and will try and bite it out.