
There is such a dearth of photographic documentation of clown breeding either in aquaria or in the wild, that for us it would be a real breakthrough to see some. We've (many of us) scoured the web for every possible story on the subject and have yet to 'see' the actual evidence for spawning, though there are several accounts of it. Forgive our skepticism. Personally, I believe what you saw sounds promising and I wish I'd seen it, too. I may have asked this already, but were you feeding live foods at all?
If they get in the mood again, please do try to get some pics if at all possible. And take copious notes, cause we are very interested in all the how's and what's and wherefore's of the whole thing! After all, if you can get them to spawn in your tank and pass along your knowledge then clown keepers here could try to do the same.