They're not even technically one organism, but colonies of independent but mostly specialized organisms. I'd be willing to bet that has something to do with the articles title

▲

andsoitis an hour ago | parent | next [-]

True jellyfish (like moon jellies, box jellyfish)are a single organism, just like you or me. Theres a single genome and one body.

Portuguese man o’ war is not a single organism at all but a siphonophore, a colony of many genetically identical but specialized individual organisms called zooids, all fused together and functionally dependent on each other.

	▲	sophrosyne42 19 minutes ago \| parent [-]
		Whats the difference between a siphonophore and a single organism? Aren't all the organs of an organism genetically identical, specialized, fused together, and functionally dependent on each other?

▲

timschmidt an hour ago | parent | prev [-]

You're thinking of Siphonophores like the Portugese Man-o-war. The Octopus Lady has a wonderful video on them: https://www.youtube.com/watch?v=ipDpbYQdFEA