Medical Research Council - London Institute of Medical Sciences

Now in our 8th year of bringing you beautiful imagery from biomedical science every day

Venomous Animals Week Nightmarish Nematocysts
22 December 2014

Nightmarish Nematocysts

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

Search The Archive

Submit An Image

What is BPoD?

BPoD stands for Biomedical Picture of the Day. Managed by the MRC London Institute of Medical Sciences the website aims to engage everyone, young and old, in the wonders of biomedicine. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.

Read More

BPoD is also available in Catalan at with translations by the University of Valencia.