How to tell the difference between bonding and aggression in Occelaris Clowns

[annie_gurl78]

I have two tankbred Occelaris Clowns in my 55g tank. I've had them for a little over a month. I believe them to still be pretty young fish. Just over the past few days, I've noticed that the larger of the two is acting aggressive towards the smaller fish. It will chase the smaller one through the tank and nip at it. Then they will swim peacefully for a bit. The larger one will then chase the smaller one again. They stay together a lot and hang out in a corner of the tank together at night. There is no sign of aggression to any of the other fish in the tank by either of them. They do swim along the back glass of the tank and kind of shake while swimming near each other. How do I tell the difference between aggression or if they are becoming a bonded pair?

In the picture, the misbarred clown is the smaller one and the one on the right is the bigger, more dominant fish.

[leebca]

One of the often-made-mistakes made by hobbyists is in the pairing of Anemonefishes. Ideally, their size difference should be as large as possible from the start. That is, one of these species you have should be no less than 1" larger than the other at their first introduction.

The closer in size each is to the other, the more aggressive the process can be, to the possible outcome of the death of one.

Also, two tank bred fishes, if from the same parents does not make for a good pairing. So you also want to be sure they are not from the same parents.

With the above said, you can figure out just how much 'extra' aggressive mating is likely to occur in your case.

[annie_gurl78]

Thanks Lee. I ordered them online so I'm not sure if they are from the same parents. There is not a huge size difference in them although the one is growing much faster then the other it seems now. And the aggression comes and goes in spurts. I'm keeping a very close eye on them and will separate them if it gets to be too much. Right now, they are nestled together peacefully in the corner of the tank.