THE GIANT PHANTOM JELLYFISH

Conjure in your mind a giant, deep-sea predator, and I bet there's a colossal squid lurking in there, perhaps with an even bigger sperm whale chasing after it.

- 

But there are plenty of other enormous hunters prowling the dark depths that still remain great mysteries to science, including the aptly named giant phantom jellyfish, Stygiomedusa gigantea (from Greek words translating roughly as the “giant jellyfish of the underworld”).

These impressively proportioned jellies are generally a deep crimson colour, with a smooth rounded bell (or 'head') a metre (3ft) or more wide, and fringed in a rippling skirt. Four ribbony arms trail behind for up to 10m (33ft) – long enough that if one of these jellies was sitting in the back row of seats in a London double-decker bus, it would be able to tap the driver on the shoulder.

Giant phantom jellyfish are members of the Ulmaridae family, together with more familiar species such as moon jellies.