Five things you (probably) never knew about sea spiders

Beautiful, bizarre or just plain scary: who knew the world's oceans were brimming with sea spiders?

This video shows them in their full glory - and here are five things you need to know about them:

1. Before you vow never to go paddling in the sea again, rest assured that none of them are poisonous to humans.

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2. There are 1,300 different species of sea spiders and they are found all over the world, from the Pacific coast of the United States, New Zealand, Australia, the Caribbean Sea and the Mediterranean Sea, to the South and North Poles. They also live in rivers.

3. Sea spiders are completely unrelated to terrestrial spiders, despite the fact that they resemble them so closely. They have four small eyes and a mouth at the end of a long tube called the proboscis.

4. The sea spider catches its prey in waterproof webs. It has a penchant for calamari and tears the flesh of its unfortunate victims. However, it doesn't seem to inject poison, relying instead on its own cunning wits to kill its food.

5. They can grow to more than 90cm - that's almost the size of a skateboard. But not to worry, they are weak and about as slow as a snail on crutches so the chances of you getting away are quite high....