However, it's not uncommon to have some achiness or discomfort for some weeks, or even months, after the event. It's not particularly clear what causes these long-term effects, but it's likely a neurotoxic effect of the urchin's venom. In any case, I have been unable to find any case reports of permanent neurological damage from an urchin sting, and her symptoms should resolve with time. Porcupines of the sea, urchin spines are like hypodermic needles that break off once deep inside you, injecting their venom. The venom from stonefish spines is delivered deep into the wound and produces excruciating pain that may last several days.
Stingrays use one or more large spines or stings on their tails as defensive weapons.
When you step on one, the ray thrusts its tail forward and upward, lacerating or puncturing your foot, ankle or leg. Multiple punctures can cause weakness, paralysis, breathing difficulty, even death. Both techniques will help slow the absorption of any venom in the wound. Do not apply a tourniquet. This will generally result in more damage than it will prevent.