Legend and fiction are full of ominous sea beasties. Mermaids! Sea serpents! Prehistoric reptiles! Giant sharks! The Norse ‘heather-back’, so vast it could be mistaken for an island!
And of course, the terrible, tentacular Kraken!
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The real sea has its own strange and wonderful monsters. Giant squid may not be quite Kraken-sized, but some are about forty feet long. (They don’t tend to rise up and attack ships, though.)
The deeper one descends into the sea, the stranger the creatures become.
Sea butterflies are like tiny, transparent snails, with wing-like flaps they use to ‘fly’ through the water in big flocks. They’re odd but rather beautiful.
The ‘pigbutt worm’ really does look like a pair of pink translucent buttocks, swimming around by themselves. The ‘Spanish dancer’ can tear off its own luminous skin, and cast it aside to distract predators. The barreleye fish has a partly transparent head!
A siphonophore may look like one creature, but it’s actually made of lots of tiny creatures working together. Some form long, treacherous, translucent nets of tendrils, which entangle other animals and sting them to death, so that they can be slowly digested…
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The Black Swallower can eat creatures larger than itself. Its jaw hinges eerily wide, and its belly stretches like elastic around the bigger animal.
More than a kilometre down, there’s no daylight at all, and the icily cold water is inky black. The only lights are glimmers of bioluminescence created by creatures of the deep.
See that little shimmer over there? It might be a creature signalling in the hope of finding a mate. It might be a predator, using its bioluminescence like a headlight to hunt prey. If you’re lucky, it’s just a bit of decaying foodstuff, glowing with bacteria.
Or… it might be a trap.