If you go swimming off the southern coast of Brazil in winter or autumn you might run into this aquatic critter – you’d certainly know about it if you did. This jellyfish – Olindias sambaquiensis – stings more swimmers than any other jellyfish in the area. Despite its prevalence, until recently there were no biochemical studies characterising its venom. Like other jellyfish, their bodies and tentacles are covered in stinging cells equipped with small organelles known as nematocysts. These nematocysts contain a small, hollow, barbed thread that everts explosively with a twisting motion and injects the venom, causing skin lesions, swelling, pain and even cardiovascular complications. When researchers analysed the toxins in the venom, they identified two new toxic proteins, cytolysins called oshem 1 and oshem 2 that cause their victim's cells to breakdown. So now we know why these little stingers are so nasty, perhaps we can find an effective treatment.
Written by Nick Kennedy
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