Try getting the little bugger and sticking him in a floating breeding net until hes needed - say for 2 weeks every 2 months - They can probably do it through the net tho - Don't give up - you will soon have lots of babies every where - sounz like the female may have been heavily pregnant and just the easiest target at the time - I'd vote need more females as well - but you could stick him in jail if its getting up ya - just don't give up on these neat fish.