Nematolebias whitei

[Fishnut]

Did anyone else buy these guys from the auction?  I definitely have a pair, but they started fighting today.  Both are holding their ground...one pecks the other, then gets pecked back...and so on and so on.

I can't find any information that says anything about fighting so I was wondering if anyone else has noticed the same thing?  Perhaps some sort of mating ritual...or they hate each other.