Tank size and maturity of the system will definitely help make a determination but unfortunately there are many other factors. I have a male Mandarin who readily eats frozen food and is fat and healthy said:
On August 6 I purchased ORA mandarin gobies a male and female mainly because when they shipped to the store that's what they sent, though I only wanted a male. I made the assumption they were a mated pair so didn't want to separate them. On Sept 16 the male started chasing the female and they had some pretty decent sparring matches; usually the female attacking the male when he approached. I've assumed it's because he's matured and become interested in her, her not so much interested in him. They have settled down and you'll see them grazing together and other times you'll see him chase her, however, not as much as before and certainly a lot less aggression. Mine are eating Nutramar Ova (prawn eggs) and Life Spectrum Small Fish pellets which they were raised on. IMO if yours is wild caught you'll certainly need to train it to accept foods other than pods prior to placing another mandarin in your tank, but territorially it may never want to share its space with another mandarin.
