Zebra Cardinals behavior

[Tati]

I recently (about a month back) got 4 Bangai Cardinals in my tank. But from the very 1st day 4 of them stay together during the night time BUT 1of then separates him/herself from the rest and stay closer to the bottom hiding behind the rock...
Any insights?

Ah, just in case it matters: 3 of them have average length of the back ‘fin’ the one who moves have it like a double of theirs’ sized.

 

[eatbreakfast]

Bangaii cardinals pr up and kill the others. This one is the first to be driven away.

 

[Tati]

Bangaii cardinals pr up and kill the others. This one is the first to be driven away.

I thoughts they r more of a ‘group’ fish... ;(

 

[eatbreakfast]

I thoughts they r more of a ‘group’ fish... ;(

In the wild they are, in captivity they are not.

 

[Lumpystarpolyp]

Seconding that this does seem like bullying behavior to me

 

[Tati]

Seconding that this does seem like bullying behavior to me

I’m sad now [emoji25]