Sexing Blue Rams

[Killi]

I purchased two blue rams from lfs and the guy just grabbed the first two he could catch. They have been together in my tank for a fortnight and there is a bit of chasing going on. Not aggression, I think one is protecting a territory. Neither have coloured up very well and I suspect they are two imature males. I have researched these fish and they show no pink colour in the belly region, however one (the fiesty one) is more male like. The other is fairly plain but has darker vertical stripes on its body. There only tank mate is a female betta and they dont bother her at all. I know photos are needed but can anyone hazard a guess. Should I buy another and have a trio in the tank to sort themselves out.
best wishes
Killi

 

[Mike Wise]

If they are mature adults, then the best way to sex the fish is by looking at the black flank patch:

Male - patch elongate with blue scales only around the edge of the patch

Female - patch more round with blue scale throughout the patch.

Both sexes can have elongated dorsal spines and even red color on the belly, depending of food. The flank patch never lies. The fish need to be 1½"/35mm for this.