The most-common world-wide jellyfish with a flat, contracting bell with hundreds (thousands in large specimens) of fine tentacles hanging beneath. The size varies from a few centimetres bell diameter with 50cm long tentacles, to bell diameters up to 2.3 meters, with 30 meter long tentacles. Fortunately the sting, although it may cause moderately-severe skin pain, usually causes no systemic symptoms, although nausea, vomiting and dizziness have been reported.
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