The voracious lion's mane jellyfish

The voracious lion's mane jellyfish
These are the first photos of a cannibal that not only eats jellyfish much larger than itself, but also two at once. Words: Peter ParksImages: Peter Parks and Chris Parks
Lizard IslandI've looked forward to each of my many filming ventures to Lizard Island, in the Great Barrier Reef, because each new trip has produced a different dominant species of drifting planktonic animal and plant.
Early on in the trip, we were near the edge of the lagoon reef only a kilometre from our landbase. Until then, by far the most dominant large drifter had been the ubiquitous moon jellyfish Aurelia aurita. But this time, pale purple Aequoria sp. were scattered among them. These were what we'd hoped to film and we duly collected them.
The lion's maneThen, something new, fist-sized and cobalt blue, drifted abreast our boat. It was soon bucketed and on board. Against the white of the bucket, it seemed a bit pinker, and I noticed that entangled among its tentacles were two Aequoria. It was a lion's mane jellyfish Cyanea sp..
For filming, we transferred a dozen moon jellyfish into a tank. Then we introduced the lion's mane, whose frilly edges were like a silky Victorian bedspread, all convolutions, pleats and tucks. Now and again, the skirt or a tentacle would brush across a moon jellyfish. These tentacles were either very sticky or else were firing off nematocysts (long, hollow threads that are either barbed or venomous) on contact.
Thinking back to when we'd caught the Cyanea, I remembered the small Aequoria in its tentacles. Could it be that this was a jellyfish-eating jellyfish? We soon knew the answer.
Source: http://www.bbc.co.uk/nature/animals/features/142index.shtml