That´s an interesting species, I think I haven´t seen it yet. When we lived on the Azores (Portugal), we often had like literally invasions of this jellyfish called the Portuguese Man O´ War. I cannot find the post that I wrote about them but here is the one that my girlfriend did...

@liltammy/lots-of-deadly-portuguese-man-o-war-have-washed-up-beach-again-azores

Have you seen these too?