Also with retics being so passive, the Motoro would destroy it when trying to breed. You'd have to have a large retic to maybe be successful and not lose the retic in the breeding.
I've heard of male rays killing a female ray trying to breed when she wasn't ready.
You'd need to have a large female retic (which you don't have as the one you have is really slow at growing) and a small Motoro male.
I don't think a male retic would attempt it with a female Motoro but I could be wrong with that.