Hi...i have a 4" female gold severum and a 3" unknown sex green severum...just today they be lip locking is this a sign of pairing or dominance? they are in my 6x2x2 with another 2 severums both 7"+ (male and female...not a pair tho) so are they pairing of fighting for space...they never did this in my 120g but haveing been in my 180g for 3-4days they have just started...thanks in advance..