My "peaceful" Fish Are Being Aggressive!

[Sugarbunny]

Hi!

Been on the the forum a few times with newbie questions which people have really helped with... this time its about my fish themselves.

When choosing fish we deliberately tried to choose breeds that were listed as peaceful and social, but they seem to be picking on each other! Firstly we only had: 2 peppered corys, 3 black neon tetras, 3 glowlight tetras and 3 columbian red tail tetras, and they seemed fine and calm. We have since introduced 3 silver mollies and 3 rainbowfish, and now the mollies are picking on each other and the rainbowfish are picking on the colombian tetras. The columbians used to be the biggest in the tank and now they no longer are... could this be why they seem to have become more recklusive? One of the rainbows is also bigger than the other 2, and he picks on the others of his type too.

We were hoping for a tranquil tank! Will they settle down by themselves or can we do anything to help them? Any advice most appreciated!

 

[Esfa]

What size tank are they in?

 

[Sugarbunny]

Tank is 60 litres - could this be too small?

 

[Scotty001]

Tank is 60 litres - could this be too small?

60l is too small to hold 3 rainbows unless they re neon / dwarf rainbows. depending on the size of the other fish if the rainbows are bosmani and a good size they may think you have put some live food n for them, when i had a problem with a tank one time i put my rainbows (3) into another tank with 10x small neon tetra, the rainbows loved me for that decision, they hunted out each an every neon that day.

 

[Miss Wiggle]

yeah i think there's a couple of problems.

1 - fish numbers, most of the fish you have are shoaling fish and will want to be in groups of 6+. The reason they like this is that they need the comfort and security of groups, if they don't have the group they feel threatened and insecure and as such will be uncharacteristically violent if thye feel at all upset.

2 - the tank is relativley small and you've quite a few fish in there, so you've got agitated and scared fish, then too many of them in a small tank.... well it's clearly a recipie for disaster to be honest.

need to re-home some fisha dn sort out the numbers

 

[Colin_T]

As suggested by Miss Wiggly Poppins all the tetras and rainbows are schooling fish that need to be kept in groups of at least 6 preferably 10 or more. These fishes naturally occur in groups of thousands out in the wild. So when you have a small number like 3 or 4 in a tank they feel very insecure and as a result they often behave badly. As soon as the numbers are increased they settle down and act more sociable.

The livebearers are probably getting hasselled by the male. Male mollies are randy little sods and will constantly chase and pester the females.

I would get rid of the mollies and rainbows and increase the number of each species of tetra to 10. Alternatively get rid of the columbian tetras and keep the mollies, and increase the other two species of tetra to 10.

 

[Sugarbunny]

Thanks for the replies!

Seems we might have made a bit of a cock up with the fish numbers! Having quite a small tank we thought getting 3 of each would be okay, and we were a bit greedy with the amount of different types of fish we wanted...

It didn't say in the shop what variety the rainbows were, it just said "rainbow" so not sure if they are dwarf or not, but looking at pictures, I think they are "banded rainbows". Will probably give them to someone we know with a bigger tank. Will see how the mollies settle once they've gone...!

 

[Colin_T]

if you can post a pic of the rainbows I might be able to identify them for you.
Otherwise check out this site.

http/members.optushome.com.au/chelmon/Melano.htm