Sudden aggression from orangeback angelfish

[iratoha]

Hello everyone. So, we have couple clowns, one orangeback angelfish, one valentini paffer, one regular small blue damsel and one bigger yellow belly damsel. 50 g tank. My yellow belly always prefer to stay behind filter tubes and there was no aggression between fish. Last week we bought powder tang. On first day angelfish bullied him a little bit, and yellow belly also tried to bite his tale in sneaky way (escaped right after). But next day everything was okay. There was peace for couple weeks. But today I noticed white wounds on yellow belly. And saw how angelfish chasing him around filter tubes. Tang also time to time blocking his way. What happened and what can I do? There were no conflicts until we bought tang. They don’t care about small damsel and don’t care about each other. Why angelfish suddenly started to attack yellowbelly? They lived together for almost 5 months.

 

[Jekyl]

You really can't know the behavior of fish without setting up a recording. They will act very different when being watched.

As for how to help, try an acclimation box. Put the aggressive fish in there for a week or 2.

 

[iratoha]

I made a video, maybe it will help

 

[iratoha]

I made a video, just posted it

 

[iratoha]

You really can't know the behavior of fish without setting up a recording. They will act very different when being watched.

As for how to help, try an acclimation box. Put the aggressive fish in there for a week or 2.

I made a video, just posted it.

 

[Jekyl]

I made a video, just posted it.

You're still in the room though. You'll have to just let the recording device sit in the room for quite a while and then review it yourself after.

While people are in view the fish will behave differently.

 

[Jay Hemdal Verified Community Expert]

Hello everyone. So, we have couple clowns, one orangeback angelfish, one valentini paffer, one regular small blue damsel and one bigger yellow belly damsel. 50 g tank. My yellow belly always prefer to stay behind filter tubes and there was no aggression between fish. Last week we bought powder tang. On first day angelfish bullied him a little bit, and yellow belly also tried to bite his tale in sneaky way (escaped right after). But next day everything was okay. There was peace for couple weeks. But today I noticed white wounds on yellow belly. And saw how angelfish chasing him around filter tubes. Tang also time to time blocking his way. What happened and what can I do? There were no conflicts until we bought tang. They don’t care about small damsel and don’t care about each other. Why angelfish suddenly started to attack yellowbelly? They lived together for almost 5 months.

That is called displaced aggression - it is more common in higher animals (think chicken pecking order, or a tribe of monkeys). I had a Red Sea exhibit once (Red Sea fish are typically more aggressive than other fish). They had a whole pecking order - a butterfly would bite an angel, who chased an angel, etc. The Sohal tang in the tank was the constant "winner".

Orangebacks can be real stinkers. This may settle down, but probably not.....if you start to see additional physical damage, you may need to separate some of the fish.