[Delphinus]

It's also equinox and that might not be so coincidental. For what it's worth, all the anemone spawnings I've had in my tanks over the years, with the exception of maybe once, they have all been inside a small threshold value of equinox or solstice (as in, if not the actual day of, within a couple days of it). I wish I kept better notes so I could say more authoritatively but I didn't, but I can say that it occured often enough that I'm pretty sure it's not so coincidental anymore.

FWIW it was the H. maginifica would spawn (quite regularly in fact) around solstice and the others (S.haddoni carpet, who was male and green.. just like yours) and BTA's would seem to spawn near equinoxes. The S.gigantea I currently have, have not spawned for me ever, which makes me wonder, could they be females and internal brooders, or could the trigger to spawn for that species be something else entirely, that's simply missing in captivity.