The spines of the weever fish can pierce your skin, which is how their venom is discharged - symptoms can include severe pain, vomiting, swelling, paralysis and even death.

With thousands of thin tentacles which can each extend to several metres long, the Lion's Manes sting can be particularly dangerous. The tentacles can still sting you even if they have broken away from the rest of the body.

Stings from this strange looking creature will leave whip-like red welts on the skin of its target and can last for two to three days, with the severe pain potentially lasting up to three hours.

You may not think these shellfish pose any harm, but they aren't called razor fish for nothing. The curved edge of the shell is razor sharp and can easily leave you with a nasty cut if you happen to step on one.