Sea Gooseberry

Image: National Museums Northern Ireland

It's an alien spaceship in outer space!

Image: joe

Passing by a nebula!

Image: Alan Moore

And... oh. It's a blue screen. Well, I guess that's the magic of Hollywood.

Sea Gooseberries are tiny, little comb jellies belonging to the genus Pleurobrachia. They're only about 2.5 cm (an inch) long, although that doesn't include two tentacles which can each reach a length of something like 15 cm (6 in).

Video: Parafilms

Like most other comb jellies, Sea Gooseberries swim around using the rhythmic beating of eight rows of tiny, iridescent cilia.

Their tentacles trail behind them and branch out to create a kind of net. The tentacles are also covered in sticky cells known as colloblasts, just to make absolutely sure that tiny prey like copepods and the like can't escape.

Video: vichigh marine

Definitely not a spaceship, then. Though I still think ATTACK OF THE SPACE GOOSEBERRIES could be a hit. All you have to do is make them big enough to pick up and eat a man and you got yourself a classic!