Found cleaning out my fuge (20 gal.) It is stocked with grape caulerpa, caulerpa mexicana and a bit of chaeto.
Lights are one 24H, but prob need replacing. Could it be a sexual stage? Just found it when doing a water change.
OK, I looked at some pics. I have seen it on rare occassion in the DT, but not for awhile. In the DT it was nice and round, not used to seeing it elongated like this, but that looks like what it is. To the trash can with it. Glad it decided to float free for me to pick out