I agree with that being female. Typically you'll only see a black spot on the dorsal on a male if there is a double flower row. I'd agree you have a male and female RD. Let them settle in for a couple of weeks like manmade said. Don't rush things. When they're ready to spawn she will still drop her tube and lay even if the male isn't on her side. Man mades suggestion is the safest way to get them to spawn. Both males and female can be unpredictable, especially during spawning with agression so it's best to be cautious.