Cornish Rock Pools Junior loves Harry Potter. A while back he noticed that a lot of rock pool creatures have scientific names that sound like spells straight from a Hogwarts classroom.

Rock pool animals have many amazing (and disgusting) tricks up their sleeves. Some are simply fearsome looking like the Devil crab in the photo above. Others have weapons and disguises.

What better way to learn their names than by chanting them spell-style to unleash their freaky abilities?

So, wands at the ready – swish and flick – here are some top spooky rock pool spells.

Sepia officinalis – Invisibility spell

Nothing can hide better than a Common cuttlefish. Sepia officianalis can change colour and texture in an instant to make it invisible to both its predators and its prey.

Marthasterias glacialis – Regrow-an-arm spell

Many sea creatures like crabs and starfish can re-grow a lost limb. Starfish like this Spiny starfish can regenerate several arms at once, so it’s not uncommon to find one with just a couple of arms and three stumps.

Here’s a spooky story for you… Some say that fishermen in the North Sea used to hack starfish in half when they found them in their nets. Starfish attacked their catch so they were determined to get rid of them. They slaughtered all the starfish they could get their hands on, certain they were reducing the population. Instead, each half of the severed starfish began to regenerate, slowly regrowing its arms. So, every time the fishermen cut one in half, they created two starfish. Soon the area was swarming with starfish.

I’m not convinced this story’s true, but it makes a great Halloween tale!

Berthella plumula – Acid squirting spell

Lots of sea slugs use poisons from their prey to defend themselves and some produce acid. The Berthella plumula can squirt out sulphuric acid from a special gland when it’s attacked. If you pick one up, it’ll make your skin blister and fall off (so best not to!).

Anemonia viridis – Harpoon stinging spell

Use this spell to unleash a secret weapon – the nematocysts. All jellyfish, anemones and other related animals have special stinging cells called nematocysts. Inside each cell is a coiled harpoon, which is fired out into anything that touches the tentacles.

Here’s a video of a pool full of Anemonia viridis eating an unfortunate fly.

Lineus longissimus – Smelly slime spell

The bootlace worm is in the Guinness Book of Records as the world’s longest animal. When fully unravelled it often stretches 7 or 8 metres but the longest ever recorded was an incredible 55 metres long. More importantly, though, its special power is giving out a stinky slime. A perfect spell to use against your enemies!

Elysia viridis – Energy-making spell

Feeling worn out? Try the Elysia viridis spell instead of over-doing the trick-or-treat sweets. This amazing little sea slug retains energy-making chloroplasts from the seaweed it eats. The chloroplasts carry on making food for the slug through photosynthesis, giving the slug an ideal energy boost.

Aplysia punctata – Smoke screen spell

Werewolves, zombies and vampires on your tail? Don’t panic – use the smoke screen spell!

Sea hares (Aplysia punctata) may look like dull brown blobs, but they are as strange as rock pool creatures get. Not only do they lay eggs in the form of pink silly-string, but they have the ability to shoot out a cloud of purple ink when attacked, providing a perfect smoke screen.

These are just a few of the bizarre things our rock-pool creatures can do. There’s plenty more rock pool magic to learn.

If you’d like to know more about the gruesome habits of the animals on our shore, have a read of my guide to revolting rockpools. You can also take part in organised events to meet the creatures for yourself. Happy Halloween!