Jellyfish: Jellyfish and sea jellies are the informal common names given to the medusa-phase of certain gelatinous members of the subphylum Medusozoa, a major part of the phylum Cnidaria. Jellyfish ...

With a baking hot summer just starting, millions of Americans have already begun flooding the nation’s beaches. They’ll face traffic jams, algae blooms, sunburn and a rising threat – painful jellyfish ...