Never seen or heard of this in my short fish life. I’ve got a Niger Trigger like 3”. Notice him being standoffish and hiding under a rock on yesterday. Didn’t even come out to eat. So I said I’ll deal with it today. Couldn’t find him, so I start moving rocks and he comes out. Immediately my 1” Picasso aims right for the nigers tail which I notice has some discoloration. Then my blue hippo which is about 3 1/2” start trying to nip and now my sailfin is doing the same. Any idea about what’s going on? I’m setting up my 10G now to put the Niger in.