You have a pair in that you have 'two' blue dolphins. But these fish don't 'pair up' in the breeding sense of the term. They're harem breeders (1 male per several females is the ideal gender ratio).

From the looks of it you have two females, but at their current stage of maturity it's hard to tell the difference between the females and juvenile males.

I say two females too.. my males at that stage are vivid blue and thicker in the body, not slinder like these.. But hey, now you know what to look for.. I wil see if I can get a pic of my 20+ one year olds in a 55 and post them..