Gary Bell/ Oceanwide / Portuguese Man Of War (Physalia physalis) jellyfish, Coffs Harbor, Solitary Islands Marine Park, New South Wales, Australia

Gary Bell/ Oceanwide / Portuguese Man Of War (Physalia physalis) jellyfish, Coffs Harbor, Solitary Islands Marine Park, New South Wales, Australia

David Shale / Siphonophore (Nanomia sp) close up of nectophores, and palpons. Gulf of Maine, Atlanic Ocean. Epipelagic species found up to 300m depth.

Hiroya Minakuchi / Jellyfish (Spirocodon saltator), Japan

Alex Mustard / Red eye medusa (Polyorchis penicillatus) with hitchhiking amphipods (Hyperia medusarum). Browning Pass, Vancouver Island, British Columbia, Canada. North East Pacific Ocean.

Franco Banfi / Freshwater jellyfish (Craspedacusta sowerbii) Lake Lugano, Ticino, Switzerland. August. Invasive species.

Franco Banfi / Freshwater jellyfish (Craspedacusta sowerbii) Lake Lugano, Ticino, Switzerland. August. Invasive species.

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

Solvin Zankl / By-the-wind sailor (Velella velella) colony. Sargasso Sea, Bermuda.

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

Richard Robinson / Featherstar (Crinoidea) on red coral (Errina novazelandiae) in Doubtful Sound, Fiordland National Park, New Zealand.

Alex Mustard / Busy coral reef community feeding on plankton, with Scalefin anthias (Pseudanthias squamipinnis), Soft corals (Dendronephthya sp.) and Fire corals (Millepora dichotoma), making up classic Red Sea scen...