Well tonight while down stairs I stopped to observe my tank while the Royal blue LED's were on. Let me set the back story. I have a rescued Blue Mandarin and Spotted Mandarin goby in the same 120 system. One from a big box store and be other from a friend. I tried introduce the to each other and a few minutes later serious ruckus broke out between then. The spotted was moved to the fuge and that's where it stayed for a few months. Then I switched out fuge and placed the spotted mandarin in the main DT. It's now been 4 months on the new sump. Back to why I stopped. When I looked into the tank I saw both gobies sitting on top of a LR bridge. Here is where it gets good. I have not seen the Blue lately and was surprised to see him next to the spotted goby. Next thing you know Holy Crap! They are courting and looks like the are actually breeding. They were in full courtship swimming to the top water column then going belly to belly and the breaking up only to do it again. I watched this for 15 minutes. They continued even after I walked to the tank. I tried to get a video but its horrible and completely blue. She looks fat already like a pregnant fish. The blue turned out to be a male who's colors are insane right now I mean has this happened to anyone? I tried to find anything on it and nothing. I would think it has happened before maybe? What do think? Cross bred Mandarine Gobies Blues and Spotted gobies.