Bully tetra?

[parfoo]

Hi

Just looking at this video - any advice? My one white finned tetra seems to chase every fish (especially in morning when lights come on) is this alarming behaviour? He’s the biggest one and seems like a bully. Tends to be more closer to the plant - not sure if being territorial? Any advice

 

[parfoo]

It’s a 90L tank and I have 6 of them. I’m thinking of getting a couple more soon also if that will help

 

[Sparx]

Does this only happen at certain times or is it constant?
A lot of fish like to develop a natural hierarchy and there will normally be one that likes to assert their dominance over the rest.
This can usually happen after feeding. Is it picking on just one other fish or is its attention is shared among the rest of them?

 

[parfoo]

Does this only happen at certain times or is it constant?
A lot of fish like to develop a natural hierarchy and there will normally be one that likes to assert their dominance over the rest.
This can usually happen after feeding. Is it picking on just one other fish or is its attention is shared among the rest of them?

It tends to be more in morning time when lights switched on and then tends to die down but still can happen. And it’s not just the one it’s all of them. He’s the biggest also

 

[GaryE]

White tipped tetras can be a bunch of different species, and yours are shot from far away and are fast, so it's hard to be sure which. The name is used and re-used, which matters because the behaviour of each species can be different.

I'll take a guess, from body shape, that you have a male from a territorial tetra species. A lot of the higher bodied tetras have that behaviour. A male stakes out an area, and in the morning, waits for females so they can spawn. He decides where his turf is and owns it when he needs it. He chases off other males, or unimpressed females.

Your tank is smaller than the numbers suggest. 90L is good if the tank is low and has a lot of space along the front, but tall tanks have wasted space for territorial fish.

I don't think you'll solve it by adding more. You'll just have less space for territory, and potentially more conflict in a confined space. There's a beautiful reddish tetra, the serpae, that has a rotten reputation as a fin nipper because they do the same thing when they're kept in a tank with a small base. They also run off other species, and do occasionally bite them.

I know it's summer, which is a problem sometimes, but what is the tank temperature?

 

[parfoo]

It’s around 26 C in tank. And they are whitefin bentosi tetras. (Hyphessobrycon bentosi)

Is it just a case of leaving it as it is then?

 

[lottabubbles]

a long long time ago I had a 55 gal aquarium with a couple of the nipping fish doing everything they could to interrupt the peace and tranquility.
the owner of the local aquarium shop suggested aquarium salt. I bought some and sure enough it was all calm again.
the problem was, I used to put the aquarium poo water on my azaleas at water change intervals. after 6 months all the azaleas were dead. that's when I quit using salt.

 

[GaryE]

Try bringing it down to 22-24. That might ruin the mood while not harming the fish in any way. Their range, according to Seriously Fish, is 20-28. I'd keep them from 22-25, with the higher temps to stimulate breeding if that were my plan. Since the aggression is breeding related, you might be able to dial them down with an environmental change. Maybe.
Sometimes, you just get an individual fish that is atypical.

I wouldn't use salt. It is a strong medication for a rainforest fish like bentosi.

 

[Colin_T]

Gary got it, male tetra defending territory from other males. If you have a few females it might let the other males hang out with them away from his corner but the only real option is a bigger tank. Lowering the temperature (as mentioned by Gary) can help too but the fish is enjoying life and has his area staked out.

Male white tip tetras usually have longer bigger dorsal (top) fins than the females.