Solvin Zankl / Portuguese man-of-war (Physalia physalis) colony, underwater Sargasso Sea, Bermuda

Solvin Zankl / Portuguese Man-of-War (Physalia physalis) close up of tentacles, Sargasso Sea, Bermuda

Michael Pitts,Michael Pitts / Portuquese man o' war (Physalia physalis) colonial siphophore, Tobago, Caribbean.

Doug Perrine / Pelagic nudibranch / Blue sea slug (Glaucus atlanticus) along with a much smaller relative, (Glaucilla sp) feeding on a Portuguese man o' war, (Physalia utriculus) Kona, Hawaii, Hawaiian Islands,...

Doug Perrine / Blue dragon / Blue seaslug (Glaucus atlanticus) feeding on a Portuguese man o' war (Physalia utriculus) along with a much smaller relative, Glaucilla sp. (upside down); Glaucus and Glaucilla store th...

Tony Wu / Blue sea slug (Glaucus atlanticus) approaching the venom-filled tentacles of a Indo-Pacific Portuguese man-of-war (Physalia utriculus). Both were washed ashore as part of a mass, multi-day stranding o...

Tony Wu / Blue sea slug (Glaucus atlanticus) that was washed ashore with a mass, multi-day stranding of thousands of Indo-Pacific Portuguese man-of-war (Physalia utriculus). This species predates Portuguese man...

Tony Wu / Top-down view of an Indo-Pacific Portuguese Man-of-War (Physalia utriculus). This is one of many thousands that were part of a mass stranding in South Africa. Atlantic ocean.

Solvin Zankl / Portuguese man-of-war (Physalia physalis) colony, Sargasso Sea, Bermuda.

Solvin Zankl / Portuguese man-of-war.(Physalia physalis) colony on the Sargasso Sea, Bermuda.

GEORGETTE DOUWMA / Bluebottle / Portuguese man-of-war (Physalia utriculus) showing its inflated float and long trailing tentacles, swept ashore by onshore winds. Cape, South Africa.

Doug Gimesy / Portuguese man-of-war (Physalia physalis) washed up on a beach among fallen leaves, Thompson Sound, Fiordland, New Zealand, January.