Ocellaris pair - should I separate them?

[Quandale applesauce]

I bought a pair of long fin ocellaris from my LFS 4 weeks ago. They are aquacultured and had been the only fish in their tank at the store for over a month. I have them in a 100gallon 4 foot tank with a canary blenny, a royal gramma, two fire fish and a hector's goby.

One is a little larger than the other. They were initially well behaved but in the last 1-2 weeks the larger one has become more aggressive. They shutter in front of each other and display and sometimes the smaller goes after the bigger one. I have attached a video. The larger one is darker in coloration. I think this is typical pairing behavior but I am concerned about the frayed fins on the smaller. Sometimes I see them on opposite ends of the tank. Then the larger one decides she wants to be aggressive and darts over.

My question is- at what point do I separate them and how do I reintroduce them? I don't want the smaller one injured or stressed to cause illness.

Thank you
QA

 

[fishguy242]

Lip locking, fin grabbing ,damage to smaller one that you are not seeing happen. til then let them work it out IMO

 

[Quandale applesauce]

Thank you for reply. This is an updated video. They are sometimes calm and sometimes go after each other like this. Still ok to leave them be?

QA

 

[fishguy242]

Seems like the smaller one is the aggressor

 

[Baldyreef]

Seems to me like they’re trying to establish Dominance over each other, eventually the more dominant one will become larger and grow into a female I would personally let them work it out unless serious injuries start to occur

 

[Mongo1.0]

They larger one normally becomes the female. It is part of the bonding process. It is hard to see the abuse the smaller ones takes, but it is part of the process.

 

[Gumbies R Us]

I would keep a close eye on them and see how it pans out. It does sound like typical clown dominance, though

 

[Blue-eyed Clowns]

What you're describing sounds like normal pairing behavior so far, but the frayed fins are the thing to watch.

Shuddering, displaying, the larger (usually darker) fish darting over, and even the smaller one pushing back, is how they settle who's who. Store "pairs" aren't always fully bonded yet, so four weeks in with a little size difference is a common time for that to heat up.

I'd separate if you see:
- Lip locking that lasts more than a few seconds
- Actual fin grabbing or bites that draw blood
- The smaller one pinned, hiding all day, or refusing food
- Fins getting worse day to day instead of holding steady

A little fray that stays the same while both still eat and swim the tank is usually OK to ride out. If it escalates, pull the aggressor (the larger one) into an acclimation box for a few days to a week, then reintroduce with lights low. That often resets them better than pulling the victim. Extra caves on opposite ends of the 100g help too.

Longfins can look ragged faster than shortfins when they scrap, so don't panic at the first nicks, just keep a close eye and have a box ready.

Mike / Blue-Eyed Clowns