Jellyfish blooms occur throughout the world. Human contact with a jellyfish induces a local
reaction of the skin, which can be painful and leave scaring. Systemic symptoms are also
observed and contact with some species is lethal. A number of studies have evaluated the
in vitro biological activity of whole jellyfish venom or of purified fractions. Hemolytic,
cytotoxic, neurotoxic or enzymatic activities are commonly observed. Some toxins have
been purified and characterized. A family of pore forming toxins specific to Medusozoans
has been identified. There remains a need for detailed characterization of jellyfish toxins to
fully understand the symptoms observed in vivo.