Jellyfish can be eaten like the species of scyphozoan but do not jump into conclusion that all species can eaten. The box jellyfish are very notorious for its very potent venom. Box jellyfish includes Chironex fleckeri, Carukia barnesi and Malo kingi, they are considered among the most venomous creatures in the world.
GMA 24 Oras reported: There are sightings of box jellyfish in Boton Pier in Subic, Zambales. According to marine biologist, box jellyfish venom is extremely dangerous. Its venom is fatal within fifteen minutes if not treated immediately.
This jelly fish has a defense mechanism called sting. When the tentacles come in contact to body skin, it pumps nematocysts with venom into the skin causing the agonizing pain and fatality in the end. Sting can be treated by applying a generous amount of vinegar on sting area. Acetic acid destroys the nematocysts that has not yet entered the blood stream. What about nematocysts on blood stream ? Do not apply water and any alcohol based liquid.
Here is the video of an actual box jellyfish. Please report if broken!