sea urchins, scientifically referred to as paracentrotus lividus, are a marine organism, and according to the ‘atlas of hazardous aquatic animals of brazil', they are the cause of half of the swimming accidents that take place in brazil - these urchins can be found in various regions of the coast of rio de janeiro state, usually burying themselves in the sandy sea floor to avoid predators.

‘ouriço-do-mar' translates as sea hedgehog - a name which requires no elaboration when considering the sharp tweezer-like thorns that extend out of the creature's main body, used to tear through the outer skin of foreign organisms to which they attach themselves.

these sharp points often release a toxic fluid which causes a burning pain, and sometimes dizziness, weakness, and even temporary paralysis - around 40% of those affected by a sea urchin do not successfully remove all of the poisonous thorns, and consequently suffer from a fever and other medical complications - thus it is important to seek medical assistance.