Goldfish Aggression

[clareanded]

In our Coldwater tank our two Goldfish (4" & 3.5") are showing a fair amount of aggression toward one another. This only happens at feeding time and is always the smaller Goldfish bashing into and chasing the larger one (who to be honest doesnt seem too bothered!).

It is a 90l tank and also includes a small Lionhead and three coldwater gobys.

Is this kind of aggression normal? It is happening on a daily basis now and has got worse over the last few weeks. All I can think is that it is all part of the scramble to get the most food?

 

[Tokis-Phoenix]

What variety/s of goldfish do you have exactly ? If you are keeping fancy and non-fancy varieties of goldfish together then this would explain the agression straight away.

ps: What sort of gobies do you have too? A lot of gobies are brackish fish and will not fair well kept in freshwater aquariums for long periods of time.

 

[clareanded]

Should have mentioned that! Both goldfish are non-fancy, just 'normal' Goldfish.

The Goby's are coldwater goby's, approx 1" in length and light grey.

 

[Tokis-Phoenix]

Should have mentioned that! Both goldfish are non-fancy, just 'normal' Goldfish.

The Goby's are coldwater goby's, approx 1" in length and light grey.

Unfortunately there are quite a few dull grey coloured gobies that come in many shades of grey, its important to indentify your exact types of gobies as these fish vary a great deal in care and habitat requirements etc- for example, there is the Knight Goby;

http/badmanstropicalfish.com/profiles/profile98.html

abd Dragon gobys;

http/www.thefishworld.co.uk/id184.htm

Etc...The best thing to do would be to get a pic/s of your gobies if you have a digital camera handy and post them here on the forum so we can ID them .



With the goldfish, getting one more goldfish may help the situation out a great deal- common goldfish when kept in pairs, it usually boils down to one goldfish becomming more dominant than the other and harrassing the weaker goldfish. In a trio of goldfish, each goldfish has more than one other goldfish to think about and so the pecking order between the goldfish is less likely to turn into a one-way situation with one goldfish picking constantly on the other.
Keep in mind though that your goldfish will eventually outgrow the 90litre tank in the future, what are the exact measurements of the tank (length, width, height) ?

With the lionhead fish, i take it you are referring to a Lionhead (or lionhead oranda) goldfish (a variety of fancy goldfish)?

 

[clareanded]

Checked the links and our Gobies are not these. I am not at home at the moment so cannot get any pics until later in the week. All I can tell you is that they were sold as "Coldwater Gobies" and at the LFS were in with Goldfish. We were told they should grow to 2" in length, like to burrow, have no swim bladders and are bottom dwellers. They change to a darker grey when on the filter housing which is black (camouflage I assume) and they also have white markings. The top fin is also coloured. There is shell in the tank and they like to hide in there.

Not really an option to get a 3rd goldfish of the same size. We moved them out of a 30l Biorb due as they out grown that. Then we added the gobies and lionhead who is not an oranda and just a lionhead goldfish.

Tank is 30" x 12" x 15"

We only have 1 live plant at the moment, if I added a couple more would that help as the goldfish wouldn't see eachother as much?

 

[afishdude]

they should outgrow that tank fairly soon. keep in mind that they get to 24"+ each when you are buying them.
plants realy isnt an option as they will eat them.

 

[Tokis-Phoenix]

Where are the white markings on the gobies (and what size/shape are they and quantity and what colour is their top fin? They may not even be gobies they may even be a type of loach or catfish), i can say for a fact though they have swimbladders, all fish have these, without a swimbladder the fish would just swim about in spirals or upside down out of control .

 

[clareanded]

Images are here - they are not great I'm afraid:







There are 3 gobies, they are no more than an inch in length and their bodies are different shades of grey and white. They have 2 dorsal fins, the bigger of which is the one further down the back and they can sucker himself onto the side of the tank. Their eyes are green but only at the bottom. Their bodies are narrow and they are lizard like in appearance.

Comments noted about plants and goldfish size. Also, having watched them eat tonight the aggressive goldfish is now harrassing the lionhead.

Thanks in advance for your advice.

 

[clareanded]

Any ideas?

 

[Tokis-Phoenix]

I really don't know what the goby is looking at the pics, however if you post the pics in the Oddballs or Brackish sections of the forum, you should be able to get more feedback on the gobies as a lot of goby keepers hang out in these sections .


With the bully goldfish harrassing the fancy lionhead goldfish, you really need to either rehome the lionhead goldfish or the bully goldfish, this is the only sound advice i can really offer that is assured to sort out the problem, once fish start to bully usually the only way to stop it is to either change the fish stocking or to remove the agresser or victem fish from the tank.

 

[clareanded]

Ok, thank you

 

[black angel]

If its just happening at feeding times then its more likely the fish are excited and what your seeing could be mating behaviour where the male nudges the female from behind and chases her. In younger fish you will see this happen a lot and doesnt mean they are about to breed, just like having an over excited puppy

And the gobies will be fish food if they are caught..

 

[clareanded]

Thanks for the info Black Angel. The aggression / mating behaviour has actually quelled recently.

Also, finally got an ID on the gobies and they are Rhinogobius Duospilus which is a cold water species tolerant of temperatures of 15 - 25 C.

 

[freshwaterfishlover]

Looks like Knigt Gobies wich are Brakish. There are Coldwater Gobies?

 

[clareanded]

Looks like Knigt Gobies wich are Brakish. There are Coldwater Gobies?

Nope, they are Coldwater Gobies as my last post confirmed.